packaged rooftop air conditioners - precedent- cooling, … · 2017. 4. 27. · 6 rt-svf55c-en...

SAFETY WARNINGOnly qualified personnel should install and service the equipment.The installation, starting up, and servicingof heating, ventilating, and air-conditioning equipment can be hazardous and requires specific knowledge andtraining. Improperly installed, adjusted or altered equipment by an unqualified person could result in death orserious injury. When working on the equipment, observe all precautions in the literature and on the tags,stickers, and labels that are attached to the equipment.

Packaged Rooftop Air Conditioners

Precedent™— Cooling, Gas/Electric

7.5Ton Standard Efficiency Rooftop Units

Service Facts

Model Numbers TSC090F YSC090F

RT-SVF55C-ENJuly 2014

Introduction

Read this manual thoroughly before operating or servicingthis unit.

Warnings, Cautions, and Notices

Safety advisories appear throughout this manual asrequired.Your personal safety and the proper operation ofthis machine depend upon the strict observance of theseprecautions.

Important Environmental Concerns

Scientific research has shown that certain man-madechemicals can affect the earth’s naturally occurringstratospheric ozone layer when released to theatmosphere. In particular, several of the identifiedchemicals that may affect the ozone layer are refrigerantsthat contain Chlorine, Fluorine and Carbon (CFCs) andthose containing Hydrogen, Chlorine, Fluorine andCarbon (HCFCs). Not all refrigerants containing thesecompounds have the same potential impact to theenvironment.Trane advocates the responsible handling ofall refrigerants-including industry replacements for CFCssuch as HCFCs and HFCs.

Important Responsible RefrigerantPractices

Trane believes that responsible refrigerant practices areimportant to the environment, our customers, and the airconditioning industry. All technicians who handlerefrigerants must be certified.The Federal Clean Air Act(Section 608) sets forth the requirements for handling,reclaiming, recovering and recycling of certainrefrigerants and the equipment that is used in theseservice procedures. In addition, some states ormunicipalities may have additional requirements thatmust also be adhered to for responsible management ofrefrigerants. Know the applicable laws and follow them.

The three types of advisories are defined as follows:

WARNINGIndicates a potentially hazardoussituation which, if not avoided, couldresult in death or serious injury.

CAUTIONsIndicates a potentially hazardoussituation which, if not avoided, couldresult in minor or moderate injury. Itcould also be used to alert againstunsafe practices.

NOTICE Indicates a situation that could result inequipment or property-damage onlyaccidents.

WARNING

Proper Field Wiring and GroundingRequired!

Failure to follow code could result in death or seriousinjury. All field wiring MUST be performed by qualifiedpersonnel. Improperly installed and grounded fieldwiring poses FIRE and ELECTROCUTION hazards.Toavoid these hazards, you MUST follow requirements forfield wiring installation and grounding as described inNEC and your local/state electrical codes.

WARNING

Personal Protective Equipment (PPE)Required!

Installing/servicing this unit could result in exposure toelectrical, mechanical and chemical hazards.

• Before installing/servicing this unit, technicians

MUST put on all PPE required for the work being

undertaken (Examples; cut resistant gloves/sleeves,

butyl gloves, safety glasses, hard hat/bump cap, fall

protection, electrical PPE and arc flash clothing).

ALWAYS refer to appropriate Material Safety Data

Sheets (MSDS)/Safety Data Sheets (SDS) and OSHA

guidelines for proper PPE.

• When working with or around hazardous chemicals,

ALWAYS refer to the appropriate MSDS/SDS and

OSHA/GHS (Global Harmonized System of

Classification and Labelling of Chemicals) guidelines

for information on allowable personal exposure

levels, proper respiratory protection and handling

instructions.

• If there is a risk of energized electrical contact, arc, or

flash, technicians MUST put on all PPE in accordance

with OSHA, NFPA 70E, or other country-specific

requirements for arc flash protection, PRIOR to

servicing the unit. NEVER PERFORM ANY

SWITCHING, DISCONNECTING, OR VOLTAGE

TESTING WITHOUT PROPER ELECTRICAL PPE AND

ARC FLASH CLOTHING. ENSURE ELECTRICAL

METERS AND EQUIPMENT ARE PROPERLY RATED

FOR INTENDED VOLTAGE.

Failure to follow instructions could result in death orserious injury.

© 2014Trane All rights reserved RT-SVF55C-EN

Introduction

Copyright

This document and the information in it are the property ofTrane, and may not be used or reproduced in whole or inpart without written permission.Trane reserves the rightto revise this publication at any time, and to make changesto its content without obligation to notify any person ofsuch revision or change.

Trademarks

All trademarks referenced in this document are thetrademarks of their respective owners.

Revision History

RT-SVF55C-EN (11 July 2014)

• Added Low Leak Economizer Factory and FieldInstalled Option

RT-SVF55C-EN 3

4 RT-SVF55C-EN

Table of Contents

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Warnings, Cautions, and Notices . . . . . . . . 2

Important Environmental Concerns . . . . . 2

Important Responsible Refrigerant Practices2

Copyright . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

General Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Performance Data . . . . . . . . . . . . . . . . . . . . . . . 6

Evaporator Fan Performance . . . . . . . . . . . . . 8

Electrical Data . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Sequence of Operation . . . . . . . . . . . . . . . . . . 16

ReliaTel Controls . . . . . . . . . . . . . . . . . . . . . 16

ReliaTel Control Cooling without an Econo-mizer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Three-Stages of Cooling . . . . . . . . . . . . . 16

ReliaTel Control Evaporator Fan Operation(for Gas Units) . . . . . . . . . . . . . . . . . . . . . 16

ReliaTel Control Evaporator Fan Operation(for Cooling Only Units) . . . . . . . . . . . . . . 17

Low Ambient Operation . . . . . . . . . . . . . . 17

ReliaTel Control Dehumidification . . . . . 17

Dehumidification Coil Purge Cycle . . . . . 17

ReliaTel Control Cooling withan Economizer . . . . . . . . . . . . . . . . . . . . . 18

Economizer Set-Up . . . . . . . . . . . . . . . . . . 18

ReliaTel Control Heating Operation (for Cool-ing Only Units) . . . . . . . . . . . . . . . . . . . . . 18

ReliaTel Control Heating Operation (for GasUnits) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Ignition Module . . . . . . . . . . . . . . . . . . . . 18

Drain Pan Condensate Overflow Switch (Op-tional) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Electromechanical Controls . . . . . . . . . . . . 19

Electromechanical Control Cooling withoutan Economizer . . . . . . . . . . . . . . . . . . . . . 19

Electromechanical Control Evaporator FanOperation (for Gas Units) . . . . . . . . . . . . . 19

Electromechanical Evaporator Fan Operation(for Cooling Only Units) . . . . . . . . . . . . . . 20

Economizer Set-Up . . . . . . . . . . . . . . . . . . 20

Electromechanical Control Cooling with anEconomizer . . . . . . . . . . . . . . . . . . . . . . . . 20

Electromechanical Control Heating Operation(for Cooling Only Units) . . . . . . . . . . . . . . .20

Electromechanical Control Heating Operation(for Gas Units) . . . . . . . . . . . . . . . . . . . . . .20

Ignition Module Low, Medium andHigh Heat . . . . . . . . . . . . . . . . . . . . . . . . . .20

Drain Pan Condensate Overflow Switch (Op-tional) . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

Pressure Curves . . . . . . . . . . . . . . . . . . . . . . . . .22

Subcooling Charging Chart . . . . . . . . . . . . . . .23

Refrigerant Circuit . . . . . . . . . . . . . . . . . . . . . . .24

RT-SVF55C-EN 5

General Data

Table 1. General data - 7½ tons (single compressor) -standard efficiency

7½ TonsT/YSC090F3,4,W

Cooling Performance(a)

Gross Cooling CapacityEER(b)

Nominal cfm/ARI Rated cfmARI Net Cooling CapacityIEER(c)

System Power (kW)

89,00011.2

3,000/2,40083,00012.27.48

Compressor

Number/Type 1/Scroll

Sound

Outdoor Sound Rating (dB)(d) 89

Outdoor Coil - Type Microchannel

ConfigurationThickness (.in)Face Area (sq. ft.)Rows/FPI

Full Face0.7116.911/23

Indoor Coil - Type Lanced

ConfigurationTube Size (in.)Face Area (sq. ft.)Rows/FPIRefrigerant ControlDrain Connection Number/Size (in.)

Full Face0.31259.894/16

Thermal Expansion Valve1¾ NPT

Outdoor Fan - Type Propeller

Number Used/Diameter (in.)Drive Type/No. SpeedscfmMotor hpMotor rpm

1/26Direct/16,0370.7

1,100

Indoor Fan - Type FC Centrifugal

Number Used/Diameter x Width (in.)Drive Type/Number Speeds/RPMMotor hp (Standard/Oversized)Motor Frame Size (Standard/Oversized)

1/12x12Belt/Variable/1,750

1.0/3.056/56

Filters(e)

Type FurnishedNumber Size Recommended

Throwaway(4) 16x25x2

Refrigerant Charge (f)

Pounds of R-410A 5.9

Heating Performance(g) (Gas/Electric Only)

Heating Input

Low Heat Input (Btu)Mid Heat Input (Btu)High Heat Input (Btu)

120,000150,000/105,000200,000/140,000

Heating Output


96,000120,000/84,000160,000/112,000

AFUE%(h)


808080

Steady State Efficiency%


808080

No. Burners


334

No. Stages


122

Gas Supply Line Pressure

Natural (minimum/maximum)LP (minimum/maximum)

4.5/14.011.0/14.0

Gas Connection Pipe Size (in)

Low Heat Mid HeatHigh Heat

1/23/43/4

(a) Cooling performance is rated at 95°F ambient, 80°F entering dry bulb, 67°F entering wet bulb. Gross capacity does not include the effect of fan motor heat. ARI capacity is net and includes the effect of fan motor heat. Units are suitable for operation to ±20% of nominal cfm. Units are certified in accordance with the Unitary Air-Conditioner Equipment certification program, which is based on ARI Standard 340/360 except AK (380V/60 Hz).

(b) EER is rated at ARI conditions and in accordance with DOE test proce-dures.

(c) Integrated Efficiency Ratio (IEER) is rated in accordance with ARI Stan-dard 340/360. The IEER rating requires that the unit efficiency be de-termined at 100%, 75%, 50% and 25% load (net capacity) at the specified in ARI Standard.

(d) Outdoor Sound Rating shown is tested in accordance with ARI Standard 270. For additional information refer to Table 6, p. 6.

(e) Optional 2” MERV 8 and MERV 13 filters also available.(f) Refrigerant charge is an approximate value. For a more precise value,

see unit nameplate and service instructions.(g) Heating performance limit settings and rating data were established

and approved under laboratory test conditions using American National Standards Institute standards. Ratings shown are for elevations up to 2000 feet. For elevations above 2000 feet, ratings should be reduced at the rate of 4% for each 1000 feet above sea level. Applicable to Gas/Electric units only.

(h)AFUE is rated in accordance with DOE test procedures.

Table 1. General data - 7½ tons (single compressor) -standard efficiency (continued)

7½ TonsT/YSC090F3,4,W

Performance Data

Table 2. Standard motor & sheave/fan speed (rpm)

TonsUnit Model

NumberFan

Sheave6 TurnsOpen

5 TurnsOpen

4 TurnsOpen

3 TurnsOpen

2 TurnsOpen

1 TurnOpen Closed

7½ T/YSC090F AK59x1” N/A 805 865 925 985 1045 1105

Note: Factory set at 3 turns open.

Table 3. Standard motor & low static drive accessory sheave/fan speed (rpm)

TonsUnit Model

NumberFan

Sheave6 Turns Open

5 Turns Open

4 Turns Open

3 Turns Open

2 Turns Open

1 Turn Open Closed

7½ T/YSC090F AK74x1” N/A 602 650 698 746 794 842

Note: Factory set at 3 turns open.

Table 4. Oversized motor & drive sheave/fan speed (rpm)

Tons Unit Model Number 6 Turns Open 5 Turns Open 4 Turns Open 3 Turns Open 2 Turns Open 1 Turn Open Closed

7½ T/YSC090F AK56x1” N/A 958 1022 1086 1150 1214

Notes: Factory set at 3 turns open.

Table 5. Oversized motor & high static drive sheave/fan speed (rpm)

Tons Unit Model Number 6 Turns Open 5 Turns Open 4 Turns Open 3 Turns Open 2 Turns Open 1 Turn Open Closed

7½ T/YSC090F BK52x1” N/A 1127 1197 1268 1338 1409

Notes: Factory set at 3 turns open.

Table 6. Outdoor sound power level - dB (ref. 10 - 12 W)

Unit Model Octave Center Frequency Overall

Tons Number 63 125 250 500 1000 2000 4000 8000 dBA

7½ T/YSC090F 91 95 90 87 84 79 75 68 89

Note: Tests follow ARI270-95.

Table 7. Static pressure drop through accessories (inches water column) - 7½ tons

Economizer with OA/RA Dampers(a)Electric Heater

Accessory (kW)(b),(c)

Unit Model Standard2" MERV

82" MERV

13100%

OA100%

RA100%

OA100%

RA100%

OA100%

RA 5-6 9-18 23-36 54

Tons Number cfm Filters(d) Filter Filter Downflow Low Leak(e) Horizontal

7½ T/YSC090F 2400 0.04 0.06 0.12 0.11 0.02 0.20 0.09 0.08 0.02 — 0.02 0.02 —

7½ T/YSC090F 3000 0.06 0.09 0.13 0.14 0.05 0.31 0.11 0.12 0.05 — 0.03 0.03 —

7½ T/YSC090F 3600 0.09 0.13 0.15 0.21 0.07 0.46 0.19 0.25 0.08 — 0.04 0.05 —

(a) OA = Outside Air and RA = Return Air.(b) Nominal kW ratings at 240, 480, 600 volts. Heaters only available on T units.(c) Electric heaters restricted on applications below 320 cfm/Ton.(d) Tested with standard filters. Difference in pressure drop should be considered when utilizing optional 2” MERV 8 and MERV 13 filters.(e) Low Leak - Downflow only.

6 RT-SVF55C-EN

Performance Data

Table 8. 7½ tons air temperature rise across electric heaters (°F)

kW Stages 7½ Tons, 3000 cfm, TSC090F3,4,W

9.0 1 9.5

18.0 1 19.0

27.0 2 28.5

36.0 2 37.9

Notes: 1. For minimum design airflow, see airflow performance table for each unit. 2. To calculate temp rise at different airflow, use the following formula:

Temp. rise across Electric Heater = kWx3414/1.08xCFM.

RT-SVF55C-EN 7

Evaporator Fan Performance

Table 9. Belt drive evaporator fan performance - 7½ tons standard efficiency -TSC090F3,4,W downflow airflow

External Static Pressure (Inches of Water)

.10 .20 .30 .40 .50 .60 .70 .80 .90 1.00

cfm rpm bhp rpm bhp rpm bhp rpm bhp rpm bhp rpm bhp rpm bhp rpm bhp rpm bhp rpm bhp

1-hp Standard Motor & Field Supplied Low Static Drive(a) 1-hp Standard Motor & Drive

2400 613 0.42 668 0.50 711 0.57 756 0.65 798 0.72 838 0.80 875 0.88 911 0.96 945 1.04 978 1.12

2700 676 0.56 733 0.69 767 0.74 808 0.83 848 0.91 886 1.00 922 1.09 956 1.18 989 1.27 1021 1.36

3000 741 0.75 793 0.89 832 0.98 863 1.04 901 1.14 936 1.24 971 1.33 1003 1.43 1036 1.53 1067 1.63

3300 807 0.98 849 1.10 897 1.26 925 1.32 954 1.40 989 1.51 1022 1.62 1053 1.73 1084 1.83 1113 1.94

3600 874 1.25 909 1.36 957 1.55 990 1.67 1015 1.73 1042 1.82 1074 1.95 1104 2.07 1134 2.18 1163 2.30

3-hp Oversized Motor & Drive

Continued


1.10 1.20 1.30 1.40 1.50 1.60 1.70 1.80 1.90 2.00


1-hp Standard Motor & High Static Drive Kit (or 2-hp Oversized Motor & Drive)

2400 1011 1.20 1041 1.28 1070 1.36 1099 1.44 1127 1.52 1153 1.60 1178 1.68 1203 1.76 1229 1.84 1252 1.92

2700 1051 1.45 1082 1.54 1111 1.63 1139 1.72 1166 1.81 1192 1.90 1217 1.98 1243 2.08 1268 2.17 1291 2.25

3000 1096 1.73 1124 1.83 1153 1.93 1180 2.03 1207 2.13 1233 2.23 1258 2.33 1283 2.43 1308 2.53 1331 2.63

3300 1142 2.05 1170 2.16 1197 2.27 1223 2.37 1249 2.48 1275 2.59 1300 2.71 1324 2.82 1347 2.92 1371 3.03

3600 1191 2.41 1218 2.53 1244 2.65 1269 2.77 1294 2.89 1319 3.01 1342 3.12 1366 3.24 1389 3.36 — —

3-hp Oversized Motor & Field Supplied High Static Drive(b)

Notes: 1. For Standard Evaporator Fan Speed (rpm), reference Table 2, p. 6. 2. Data includes pressure drop due to standard filters and wet coils. No accessories or options are included in pressure drop data. 3. Refer to Table 7, p. 6 to determine additional static pressure drop due to other options/accessories. 4. 1-hp Fan Motor Heat (MBh) = 2.829 x Fan bhp+.4024. 3-hp Fan Motor Heat (MBh) = 2.900 x Fan bhp+.4750 5. Factory supplied motors, in commercial equipment, are definite purpose motors, specifically designed and tested to operate reliably and continuously

at all cataloged conditions. Using the full horsepower range of our fan motors as shown in our tabular data will not result in nuisance tripping or premature motor failure. Our product's warranty will not be affected.

(a) Field Supplied Fan Sheave AK74 and Belt AX35 (b) Field Supplied Fan Sheave BK52 and Belt BX30

8 RT-SVF55C-EN


Table 10. Belt drive evaporator fan performance - 7½ tons standard efficiency -TSC090F3,4,W horizontal airflow


.10 .20 .30 .40 .50 .60 .70 .80 .90 1.00



2400 681 0.52 726 0.60 770 0.69 811 0.77 852 0.85 892 0.94 931 1.02 969 1.11 1007 1.20 1046 1.31

2700 754 0.72 796 0.81 835 0.90 874 0.99 910 1.08 947 1.18 983 1.27 1018 1.37 1052 1.47 1087 1.57

3000 828 0.97 868 1.07 903 1.17 938 1.27 973 1.37 1005 1.47 1039 1.57 1072 1.68 1103 1.78 1135 1.90

3300 904 1.26 940 1.37 974 1.48 1004 1.59 1037 1.71 1069 1.82 1098 1.93 1129 2.04 1159 2.15 1188 2.27

3600 979 1.62 1013 1.74 1045 1.86 1074 1.98 1103 2.10 1133 2.22 1162 2.35 1189 2.46 1217 2.58 1245 2.71


Continued


1.10 1.20 1.30 1.40 1.50 1.60 1.70 1.80 1.90 2.00



2400 1083 1.42 1119 1.52 1153 1.63 1185 1.73 1218 1.84 1249 1.95 1278 2.06 1307 2.16 1337 2.28 1364 2.38

2700 1120 1.67 1154 1.79 1188 1.91 1220 2.02 1252 2.14 1283 2.26 1313 2.39 1342 2.51 1370 2.63 1397 2.74

3000 1166 2.00 1197 2.12 1227 2.23 1256 2.34 1288 2.47 1318 2.61 1347 2.73 1377 2.87 1406 3.01 1433 3.14

3300 1217 2.39 1246 2.51 1274 2.63 1302 2.75 1330 2.88 1357 3.00 1384 3.13 1413 3.27 1441 3.42 — —

3600 1272 2.83 1299 2.96 1326 3.09 1352 3.22 1378 3.35 — — — — — — — — — —





RT-SVF55C-EN 9


Table 11. Belt drive evaporator fan performance - 7½ tons standard efficiency with gas heat -YSC090F3,4,W low &medium gas heat downflow airflow


.10 .20 .30 .40 .50 .60 .70 .80 .90 1.00



2400 655 0.47 707 0.55 758 0.64 802 0.72 845 0.80 886 0.88 925 0.97 961 1.05 997 1.14 1028 1.22

2700 724 0.64 770 0.73 817 0.83 861 0.92 900 1.02 939 1.11 976 1.20 1011 1.30 1045 1.39 1077 1.49

3000 794 0.86 837 0.96 878 1.06 920 1.17 958 1.27 994 1.38 1029 1.48 1063 1.58 1096 1.69 1128 1.79

3300 865 1.12 905 1.23 942 1.34 980 1.45 1018 1.57 1053 1.69 1085 1.80 1117 1.92 1148 2.03 1179 2.14

3600 937 1.43 973 1.55 1008 1.67 1042 1.79 1077 1.91 1112 2.05 1144 2.18 1174 2.30 1203 2.42 1232 2.55


Continued


1.10 1.20 1.30 1.40 1.50 1.60 1.70 1.80 1.90 2.00


1-hp Standard Motor & Drive

2400 1060 1.30 1091 1.39 1120 1.48 1150 1.57 1178 1.65 1204 1.74 1231 1.83 1256 1.91 1281 2.00 1304 2.09

2700 1109 1.58 1139 1.68 1167 1.77 1195 1.86 1223 1.96 1249 2.06 1275 2.16 1301 2.26 1325 2.35 1349 2.45

3000 1158 1.90 1188 2.00 1216 2.11 1244 2.21 1271 2.32 1296 2.42 1321 2.53 1346 2.64 1371 2.75 1393 2.85

3300 1209 2.26 1238 2.37 1265 2.49 1293 2.61 1319 2.72 1344 2.84 1369 2.95 1393 3.07 1416 3.18 1441 3.30

3600 1261 2.67 1289 2.80 1316 2.92 1342 3.04 1368 3.17 1393 3.30 1419 3.43 — — — — — —





10 RT-SVF55C-EN


Table 12. Belt drive evaporator fan performance - 7½ tons standard efficiency with gas heat -YSC090F3,4,W low &medium gas heat - horizontal airflow


.10 .20 .30 .40 .50 .60 .70 .80 .90 1.00



2400 739 0.61 783 0.69 825 0.77 866 0.85 903 0.93 941 1.02 978 1.11 1013 1.20 1046 1.28 1078 1.37

2700 821 0.85 861 0.94 898 1.03 935 1.12 972 1.21 1005 1.30 1038 1.39 1072 1.49 1104 1.59 1135 1.69

3000 904 1.14 940 1.24 974 1.34 1008 1.44 1042 1.54 1075 1.65 1105 1.74 1135 1.85 1164 1.95 1195 2.06

3300 987 1.49 1020 1.60 1052 1.71 1083 1.82 1113 1.93 1144 2.04 1174 2.16 1203 2.27 1230 2.38 1257 2.49

3600 1071 1.92 1101 2.04 1131 2.15 1160 2.27 1188 2.39 1216 2.51 1244 2.64 1272 2.76 1298 2.88 1323 3.00

3-hp Oversized Motor & Drive 3-hp Oversized Motor & Field Supplied Drive(b)

Continued


1.10 1.20 1.30 1.40 1.50 1.60 1.70 1.80 1.90 2.00



2400 1110 1.46 1140 1.55 1169 1.64 1198 1.73 1225 1.82 1251 1.91 1277 2.01 1301 2.10 1326 2.19 1350 2.28

2700 1165 1.78 1195 1.88 1223 1.98 1251 2.08 1277 2.18 1304 2.29 1330 2.39 1355 2.49 1378 2.59 1402 2.70

3000 1224 2.17 1252 2.28 1279 2.39 1306 2.49 1332 2.60 1358 2.71 1383 2.83 1407 2.94 1430 3.05 1454 3.16

3300 1283 2.61 1311 2.73 1338 2.85 1364 2.97 1389 3.09 1413 3.21 1439 3.33 — — — — — —

3600 1349 3.13 1373 3.25 1398 3.38 — — — — — — — — — — — — — —





RT-SVF55C-EN 11


Table 13. Belt drive evaporator fan performance - 7½ tons standard efficiency with gas heat -YSC090F3,4,W high gas heatdownflow airflow


.10 .20 .30 .40 .50 .60 .70 .80 .90 1.00



2400 675 0.51 727 0.60 772 0.68 815 0.76 857 0.85 896 0.93 935 1.02 971 1.11 1006 1.19 1041 1.29

2700 748 0.70 793 0.80 837 0.89 877 0.98 915 1.08 952 1.17 988 1.27 1022 1.37 1056 1.47 1089 1.57

3000 821 0.94 862 1.04 903 1.15 941 1.25 976 1.35 1011 1.46 1045 1.57 1077 1.67 1109 1.78 1140 1.89

3300 895 1.23 932 1.34 970 1.46 1007 1.58 1040 1.69 1072 1.79 1104 1.91 1134 2.03 1164 2.15 1194 2.27

3600 969 1.57 1004 1.70 1038 1.82 1073 1.95 1106 2.07 1136 2.19 1166 2.32 1195 2.44 1223 2.57 1251 2.70


Continued


1.10 1.20 1.30 1.40 1.50 1.60 1.70 1.80 1.90 2.00



2400 1074 1.37 1105 1.46 1136 1.55 1165 1.64 1194 1.73 1222 1.83 1250 1.92 1275 2.00 1301 2.10 1326 2.18

2700 1121 1.66 1151 1.76 1181 1.86 1211 1.97 1238 2.06 1266 2.17 1292 2.27 1318 2.37 1344 2.47 1369 2.57

3000 1170 2.00 1199 2.11 1229 2.22 1256 2.33 1285 2.44 1311 2.55 1336 2.66 1363 2.77 1388 2.89 1413 3.00

3300 1223 2.39 1251 2.50 1279 2.62 1305 2.74 1333 2.87 1358 2.98 1384 3.11 1408 3.23 1434 3.35 — —

3600 1279 2.83 1305 2.95 1331 3.08 1357 3.21 1383 3.34 — — — — — — — — — —





12 RT-SVF55C-EN


Table 14. Belt drive evaporator fan performance - 7½ tons standard efficiency with gas heat -YSC090F3,4,W high gas heathorizontal airflow


.10 .20 .30 .40 .50 .60 .70 .80 .90 1.00



2400 776 0.70 819 0.79 859 0.87 898 0.96 936 1.05 972 1.13 1007 1.22 1039 1.31 1071 1.40 1102 1.49

2700 863 0.97 901 1.07 938 1.16 974 1.26 1009 1.36 1043 1.46 1075 1.55 1106 1.65 1136 1.75 1165 1.85

3000 951 1.31 985 1.42 1019 1.52 1052 1.63 1084 1.73 1116 1.84 1146 1.95 1176 2.06 1205 2.17 1232 2.28

3300 1039 1.72 1071 1.84 1102 1.95 1132 2.07 1162 2.18 1191 2.30 1220 2.42 1248 2.54 1275 2.66 1302 2.78

3600 1128 2.21 1157 2.34 1186 2.46 1214 2.59 1242 2.71 1269 2.84 1296 2.97 1322 3.10 1348 3.23 1373 3.36

3-hp Oversized Motor & Drive 3-hp Oversized Motor & Field Supplied High Static Drive(b)

Continued


1.10 1.20 1.30 1.40 1.50 1.60 1.70 1.80 1.90 2.00



2400 1132 1.58 1161 1.68 1189 1.77 1216 1.86 1242 1.95 1268 2.04 1293 2.13 1318 2.23 1342 2.33 1364 2.42

2700 1194 1.95 1222 2.05 1249 2.16 1276 2.26 1301 2.37 1327 2.48 1350 2.57 1374 2.68 1398 2.78 1421 2.88

3000 1260 2.39 1286 2.50 1312 2.61 1337 2.72 1363 2.84 1387 2.96 1410 3.07 1434 3.19 1457 3.31 — —

3300 1328 2.90 1353 3.02 1378 3.14 1402 3.26 1426 3.39 — — — — — — — — — —

3600 — — — — — — — — — — — — — — — — — — — —





RT-SVF55C-EN 13

Electrical Data

Table 15. Unit wiring - standard efficiency

Standard Indoor Fan Motor(a) Oversized Indoor Fan Motor

TonsUnit Model

NumberVoltageRange MCA

Max Fuse Size or Max Circuit

Breaker MCA


Breaker

7½ T/YSC090F3 187-253 38.2 60 44.0 60

7½ T/YSC090F4 414-506 19.5 30 22.4 35

7½ T/YSC090FW 517-633 14.7 20 16.7 25

(a) The standard motor for the 3-phase models is a Belt Drive Motor.

Table 16. Unit wiring with electric heat (single point connection) - standard efficiency

Standard Indoor Motor(a) Oversized Indoor Motor

TonsUnit Model

NumberHeater Model

NumberHeater kW

RatingControl Stages MCA


Breaker MCA


Breaker

208/230 Volts Three Phase

7½ TSC090F3 BAYHTRW309* 6.8/9.0 1 38.2/38.2 60/60 44.0/44.0 60/60

7½ TSC090F3 BAYHTRW318* 13.5/18.0 1 51.4/58.6 60/60 58.6/65.9 60/70

7½ TSC090F3 BAYHTRW327* 20.3/27.0 2 74.9/85.8 80/90 82.1/93.0 90/100

7½ TSC090F3 BAYHTRW336* 27.0/36.0 2 98.4/112.8 100/125 105.6/120.0 110/125

460 Volts Three Phase

7½ TSC090F4 BAYHTRW409* 9.0 1 19.5 30 22.4 35

7½ TSC090F4 BAYHTRW418* 18.0 1 29.3 30 32.9 35

7½ TSC090F4 BAYHTRW427* 27.0 2 42.8 45 46.4 50

7½ TSC090F4 BAYHTRW436* 36.0 2 56.3 60 59.9 60

575 Volts Three Phase

7½ TSC090FW BAYHTRWW18* 18.0 1 23.4 25

7½ TSC090FW BAYHTRWW27* 27.0 2 34.3 35

7½ TSC090FW BAYHTRWW36* 36.0 2 45.0 45

(a) The Standard Motor for the 3-phase models is a Belt Drive Motor.

Table 17. Electrical characteristics - compressor motor and condenser motor - 60 cycle - standard efficiency

Compressor Motors Condenser Fan Motors

Unit Model Amps(a) Amps(a)

Tons Number No. Volts Phase hp(b) rpm RLA LRA No. Volts Phase hp FLA LRA

7½ T/YSC090F3 1 208-230 3 6.7 3500 25.0 164.0 1 208-230 1 0.70 3.3 9.5

7½ T/YSC090F4 1 460 3 6.7 3500 12.8 100.0 1 460 1 0.70 1.8 5.5

7½ T/YSC090FW 1 575 3 6.7 3500 9.6 78.0 1 575 1 0.70 1.3 3.2

(a) Amp draw for each motor; multiply value by number of motors to determine total amps.(b) hp for each compressor.

14 RT-SVF55C-EN

Electrical Data

Table 18. Electrical characteristics - standard evaporator fan motor - 60 cycle - direct or belt drive - standard efficiency

Unit Model Direct or Belt Amps

Tons Number Drive No. Volts Phase hp FLA LRA

7½ T/YSC090F3 Belt Drive 1 208-230 3 1.00 3.60-3.50 12.50

7½ T/YSC090F4 Belt Drive 1 460 3 1.00 1.70 12.50

7½ T/YSC090FW Belt Drive 1 575 3 1.00 1.40 10.00

Table 19. Electrical characteristics - oversized evaporator fan motor - 60 cycle - belt drive - standard efficiency

Unit Model Amps

Tons Number No. Volts Phase hp FLA LRA

7½ T/YSC090F3 1 208-230 3 3.00 9.40-9.20 52.40

7½ T/YSC090F4 1 460 3 3.00 4.60 26.30

7½ T/YSC090FW 1 575 3 3.00 3.40 29.40

Table 20. Electrical characteristics — power exhaust (cooling and gas/electric)

Tons Volts Phase hp rpm FLA LRA

7½ 208-230 1 0.87 1075(a) 5.7 16.3

7½ 460 1 0.87 1075(a) 3.3 6.8

7½ 575 1 0.87 1075(a) 2.3 5.4

(a) Two speed.

Table 21. Electrical characteristics - inducer motor

Unit Model Number Stages hp rpm Volts Phase LRA

YSC090F**(L,X) 1 1/35 3000 208-230 1 0.6

YSC090F**(M,H,Y,Z) 2 1/15 2800/3350 208-230 1 0.4

RT-SVF55C-EN 15

Sequence of Operation

These units are offered with two control options,electromechanical and ReliaTel™.

Note: Refer to the unit nameplate: If the 9th digit of themodel number = R, proceed with the followingSequence of Operation. If the 9th digit of the modelnumber = E, proceed with “ElectromechanicalControls,” p. 19.

Note: The Condensate Overflow Switch (COF) (optional)will shut the unit down if the float is raised and theswitch is closed.

ReliaTel Controls

ReliaTel Control is a microelectronic control feature, whichprovides operating functions that are significantlydifferent than conventional electromechanical units.Themaster module is the ReliaTel Refrigeration Module(RTRM).

The RTRM provides compressor anti-short cycle timingfunctions through minimum “Off” and “On” timing toincrease reliability, performance and to maximize unitefficiency.

Upon power initialization, the RTRM performs self-diagnostic checks to insure that all internal controls arefunctioning. It checks the configuration parametersagainst the components connected to the system.

The LED located on the RTRM module is turned “On”within one second after power-up if all internal operationsare okay.

ReliaTel Control Cooling without anEconomizer

When the system switch is set to the “Cool” position andthe zone temperature rises above the cooling setpointcontrol band, the RTRM energizes the (K9) relay coillocated on the RTRM. When the K9 relay contacts close,the compressor contactor (CC1) coil is energized providedthe low pressure control (LPC1), high pressure control(HPC1) and discharge line thermostat (TDL 1) are closed.When the CC1 contacts close, compressor (CPR1) and theoutdoor fan motor (ODM) start to maintain the zonetemperature to within ± 2ºF of the sensor setpoint at thesensed location.

If the first stage of cooling can not satisfy the coolingrequirement, the RTRM energizes the (K10) relay coillocated on the RTRM.When the (K10) relay contacts close,the compressor contactor (CC2) coil is energized providedthe low pressure control (LPC2), high pressure control(HPC2) and discharge line thermostat (TDL 2) are closed.When the CC2 contacts close, compressor (CPR2) starts to

maintain the zone temperature to within ± 2ºF of the sensorsetpoint at the sensed location.

Three-Stages of Cooling1

When the unit is configured for three-stage cooling, andthe system switch is set to the cool position and the zonetemperature rises above the cooling setpoint control band,the RTRM energizes the (K10) relay coil located on theRTRM. When the (K10) relay contacts close, compressorcontactor (CC2) is energized.This is the smaller of the twocompressors (CPR2).This staging order is oppositestandard staging order.

If the first stage of cooling can not satisfy the coolingrequirement, the RTRM energizes the (K9) relay coil andde-energizes the (K10) relay coil on the RTRM. Compressorcontactor (CC1) is energized, bringing on the larger of thetwo compressors (CPR1). Compressor contactor (CC2) isde-energized, turning off the smaller compressor.

If the second stage of cooling can not satisfy the coolingrequirement, the RTRM keeps the (K9) relay coil energizedand energizes the (K10) relay coil. Compressor contactors(CC1) and (CC2) are energized, and both compressors(CPR1 and CPR2).

Lead/Lag is disabled with three-stage cooling. A unitconfigured for three-stage cooling and controlled with athermostat will operate as a two-stage unit.

ReliaTel Control Evaporator Fan Operation(for Gas Units)

When the fan selection switch is set to the“Auto” position,the RTRM energizes the (K6) relay coil approximately 1second after energizing the compressor contactor coil(CC1) in the cooling mode. In the heating mode, the RTRMenergizes the (K6) relay coil approximately 45 second aftergas ignition. Closing the (K6) contacts on the RTRMenergizes the indoor fan relay (F) coil to start the indoor fanmotor (IDM).

The RTRM de-energizes the fan relay (F) approximately 60seconds after the cooling requirement has be satisfied toenhance unit efficiency. When the heating cycle isterminated, the indoor fan relay (F) coil is de-energizedapproximately 90 seconds after the heating requirement.

When the fan selection switch is set to the “On” position,the RTRM keeps the indoor fan relay coil (F) energized forcontinuous fan motor operation.

When the unit is equipped with the optional clogged filterswitch, wired between terminals J7-3 and J7-4 on theReliaTel Options Module (RTOM), the RTRM produces ananalog output if the clogged filter switch (CFS) closes fortwo minutes after a request for fan operation. When the

1 High efficiency units only.

16 RT-SVF55C-EN


system is connected to a remote panel, the “SERVICE”LED will be turned on when this failure occurs.

ReliaTel Control Evaporator Fan Operation(for Cooling Only Units)

When the fan selection switch is set to the“Auto” position,the RTRM energizes the (K6) relay coil approximately 1second after energizing the compressor contactor coil(CC1) in the cooling mode. In the heating mode, the RTRMenergizes the (K6) relay coil approximately 1 secondbefore energizing the electric heat contactors. Closing the(K6) contacts on the RTRM energizes the indoor fan relay(F) coil to start the indoor fan motor (IDM).The RTRM de-energizes the fan relay (F) approximately 60 seconds afterthe cooling requirement has be satisfied to enhance unitefficiency.

When the heating cycle is terminated, the indoor fan relay(F) coil is de-energized at the same time as the heatercontactors.

When the fan selection switch is set to the “On” position,the RTRM keeps the indoor fan relay coil (F) energized forcontinuous fan motor operation.

When the unit is equipped with the optional clogged filterswitch, wired between terminals J7-3and J7-4 on theReliaTel Options Module (RTOM), the RTRM produces ananalog output if the clogged filter switch (CFS) closes fortwo minutes after a request for fan operation.

When the system is connected to a remote panel, the“SERVICE” LED will be turned on when this failure occurs.

Low Ambient Operation

During low ambient operation, outside air temperaturebelow 55°F, the RTRM will cycle the compressor andoutdoor fan motor“Off” for approximately 3 minutes afterevery 10 minutes of accumulated compressor run time.The indoor fan motor (IDM) will continue to operate duringthis evaporator defrost cycle (EDC) and the compressorand outdoor fan will return to normal operation once thedefrost cycle has terminated and the compressor “Off”time delay has been satisfied.

Note: (For units with the dehumidification option) Whenin dehumidification mode, the unit will not cycle asdescribed above.The unit will run continuously indehumidification mode at all ambient conditionsabove 40ºF. Dehumidification is disabled atambient conditions below 40ºF.

ReliaTel Control Dehumidification

Single Compressor Units

On a call for dehumidification, the reheat valve isenergized and the compressor is turned on. When thehumidity control setpoint is satisfied, the valve is de-energized and the compressor is turned off. If there is a callfor cooling or heating from the space temperaturecontroller, i.e. zone sensor or thermostat, while in reheat,

the reheat valve is de-energized and the compressorcontinues to run, or the heat is turned on.The 3 minutecompressor on and off times are still active duringcompressor operation.

Dual Compressor Units

The dehumidification cycle is only permitted above 40ºF asindicated above and is not permitted during a heatingcycle or during a demand for 2nd stage cooling. Otherwise,when an installed zone humidity sensor indicates arelative humidity equal to or greater than the RH set pointas adjusted on the ReliaTel Options Module (RTOM), adehumidification cycle is initiated.The Sequence ofOperation for the dehumidification cycle is identical to thatof the second stage ReliaTel cooling cycle, except that thehot gas reheat valve (RHV) is energized, allowing air fromthe evaporator to be reheated. Also, any installed fresh airdamper is driven to minimum position.Thedehumidification cycle is terminated by initiation of aheating cycle or a 2nd stage cooling cycle or when zonehumidity is reduced to 5% below the R.H. set point. In theabsence of a zone humidity sensor input, an on/off inputfrom a zone humidistat is used to initiate/terminate thedehumidification cycle.

Dehumidification takes priority over a call for one-stagecooling.

Heating or two-stage cooling takes priority overdehumidification, and a relative humidity sensor takespriority over a humidistat.

Dehumidification Coil Purge Cycle

On multiple circuit units with dehumidification/reheatconfigured, a purge cycle will be active for compressorreliability.The purpose of this function is to properlydistribute refrigerant and lubricant throughout the systemby temporarily switching to the unused section of the coilfor 3 minutes (purge cycle).The function operates asfollows:

1. A purge cycle will be initiated after 90 minutes ofaccumulated compressor run time in only one mode:cooling or dehumidification, without transitioning tothe other mode.

2. A purge cycle will consist of transitioning to the modethat hasn’t run in 90 minutes of total compressoroperation.The cycle will last for a period of 3 minutes.

3. The 90-minute cycle count will be reset anytime thereis a normal transition between cooling anddehumidification.Transitioning from one of thesemodes to any other mode (off or heat) will not reset thecounter.

4. If the purge cycle is a cooling cycle, only the first circuitwill be activated. If it is a dehumidification cycle thenthe normal 2-compressor dehumidification modecycle will be used.

5. The purge cycle will ignore the low ambientdehumidification lockout feature.

RT-SVF55C-EN 17


6. A purge cycle takes priority over normal cooling ordehumidification requests, but will discontinue for allhigh priority lockouts and alarms.

ReliaTel Control Cooling withan Economizer

The economizer is utilized to control the zone temperatureproviding the outside air conditions are suitable. Outsideair is drawn into the unit through modulating dampers.When cooling is required and economizing is possible, theRTRM sends the cooling request to the unit economizeractuator (ECA) to open the economizer damper.The RTRMtries to cool the zone utilizing the economizer to slightlybelow the zone temperature setpoint. If the mixed airsensor (MAS) senses that the mixed air temperature isbelow 53°F, the damper modulates toward the closedposition. If the zone temperature continues to rise abovethe zone temperature setpoint control band and theeconomizer damper is full open for 5 minutes, the RTRMenergizes the compressor contactor (CC1). If the zonetemperature continues to rise above the zone temperaturesetpoint control band and the economizer damper is fullyopen, the RTRM energizes the compressor contactor(CC2).

The ECA continues to modulate the economizer damperopen/closed to keep the mixed air temperature that iscalculated by the RTRM.

If economizing is not possible, the ECA drives the damperto the minimum position setpoint when the indoor fanrelay (F) is energized and allows mechanical coolingoperation.

When the unit is equipped with the optional fan failureswitch, wired between terminals J7-5 and J7-6 on theRTOM, the RTRM will stop all cooling functions andproduce an analog output if the fan failure switch (FFS)does not open within 40 seconds after a request for fanoperation. When the system is connected to a remotepanel, the “SERVICE” LED will flash when this failureoccurs.

Note: For units equipped with the dehumidificationoption, if the unit is economizing, the damperresets to minimum position while indehumidification mode.

Economizer Set-Up

Adjusting the minimum position potentiometer located onthe unit economizer actuator (ECA) sets the requiredamount of ventilation air.

Two of the three methods for determining the suitability ofthe outside air can be selected utilizing the enthalpypotentiometer on the ECA, as described below:

1. AmbientTemperature - controlling the economizingcycle by sensing the outside air dry bulb temperature.Table 22, p. 18 lists the selectable dry bulb values bypotentiometer setting.

2. Reference Enthalpy - controlling the economizer cycleby sensing the outdoor air humidity. Table 22, p. 18lists the selectable enthalpy values by potentiometersetting. If the outside air enthalpy value is less than theselected value, the economizer is allowed to operate.

3. Comparative Enthalpy - utilizing a humidity sensor anda temperature sensor in both the return air stream andthe outdoor air stream, the unit control processor(RTRM) will be able to establish which conditions arebest suited for maintaining the zone temperature, i.e.indoor conditions or outdoor conditions.Thepotentiometer located on the ECA is non-functionalwhen both the temperature and humidity sensors areinstalled.

ReliaTel Control Heating Operation (forCooling Only Units)

When the system switch is set to the “Heat” position andthe zone temperature falls below the heating setpointcontrol band, the RTRM energizes (K1) relay coil.When the(K1) relay contacts close, located on the RTRM, the firststage electric heat contactor (AH or AH & CH) is energized.

If the first stage of electric heat can not satisfy the heatingrequirement, the RTRM energizes (K2) relay coil.When the(K2) relay contacts close, located on the RTRM, the secondstage electric heat contactor (BH) is energized, ifapplicable.The RTRM cycles both the first and secondstages of heat “On” and “Off” as required to maintain thezone temperature setpoint.

ReliaTel Control Heating Operation (forGas Units)

When the system switch is set to the “Heat” position andthe zone temperature falls below the heating setpointcontrol band, a heat cycle is initiated when the RTRMcommunicates ignition information to the Ignition module(IGN).

Ignition Module

Two-stage (IGN) runs self-check (including verification thatthe gas valve is de-energized). (IGN) checks the high-limitswitches (TC01 &TC02) for normally closed contacts, thepressure switch (PS) for normally open contacts, and theflame rollout (FR) switch for continuity. (IGN) energizesinducer blower on high speed to check pressure switch

Table 22. Potentiometer settings

Potentiometer Setting Dry Bulb Reference Enthalpy

A 73°F (22.8ºC) 27 Btu/lb (63 kJ/kg)

B 70°F (21.1ºC) 25 Btu/lb (58 kJ/kg)

C 67°F(a) (19.4ºC)

(a) Factory settings

23 Btu/lb (53 kJ/kg)

D 63°F (17.2ºC) 22 Btu/lb (51 kJ/kg)

E 55ºF (12.8ºC) 19 Btu/lb (44 kJ/kg)

18 RT-SVF55C-EN


closure. If the pressure switch is closed, the inducer blowerstarts a 20-second pre-purge (15 seconds on high speedfollowed by 5 seconds on low speed). If the pressureswitch (PS) is still open, the inducer blower will continue tobe energized on high speed until pressure switch closure.After pre-purge completes, the (IGN) energizes the firststage of the gas valve, initiates spark for 2 secondsminimum, 7 seconds maximum (ignition trial) and detectsflame and de-energizes spark. From this point, a fixed 45second indoor blower delay on timing starts. After theindoor blower delay on is completed, the (IGN) energizesthe indoor blower.The (IGN) enters a normal operatingloop where all inputs are continuously monitored. If thefirst stage of gas heat can not satisfy the heatingrequirement, the thermostat closes W2.The (IGN)energizes the second stage of the gas valve and the secondstage of inducer blower. When the zone thermostat issatisfied, the (IGN) de-energizes the gas valve.The (IGN)senses loss of flame.The (IGN) initiates a 5 second inducerblower post purge.The (RTRM) initiates a second indoorblower delay off.

If the burner fails to ignite, the ignition module will attempttwo retries before locking out.The green LED will indicatea lock out by two fast flashes. An ignition lockout can bereset by;

1. Opening for 3 seconds and closing the main powerdisconnect switch.

2. Switching the “Mode” switch on the zone sensor to“OFF” and then to the desired position.

3. Allowing the ignition control module to resetautomatically after one hour. Refer to the “IgnitionControl Module Diagnostics” section for the LEDdiagnostic definitions.

When the fan selection switch is set to the“Auto” position,the RTRM energizes the indoor fan relay (F) coilapproximately 30 second after initiating the heating cycleto start the indoor fan motor (IDM).

Drain Pan Condensate Overflow Switch(Optional)

This input incorporates the Condensate Overflow Switch(COF) mounted on the drain pan and the ReliaTel OptionsModule (RTOM). When the condensate level reaches thetrip point for 6 continuous seconds, the RTOM will shutdown all unit function until the overflow condition hascleared.The unit will return to normal operation after 6continuous seconds with the COF in a non-trippedcondition. If the condensate level causes the unit toshutdown more than 2 times in a 3 day period, the unit willbe locked-out of operation. A manual reset of thediagnostic system through the zone sensor or BuildingAutomation System (BAS) will be required. Cycling unitpower will also clear the fault.

Electromechanical Controls

These units are offered with two control options,electromechanical and ReliaTel controls.The ReliaTelcontrols is a microelectronic control feature, whichprovides operating functions that are significantlydifferent than conventional electromechanical units.

Electromechanical Control Coolingwithout an Economizer

When the thermostat switch is set to the “Cool” positionand the zone temperature rises above the cooling setpoint,the thermostatY contacts close.The compressorcontactor (CC1) coil is energized provided the low pressurecontrol (LPC1), high pressure control (HPC1) anddischarge line thermostat (TDL 1) are closed. When the(CC1) contacts close, compressor (CPR1) and the outdoorfan motor (ODM) start. If the first stage of cooling can notsatisfy the cooling requirement, the thermostat closesY2.The compressor contactor (CC2) coil is energized providedthe low pressure control (LPC2), high pressure control(HPC2) and discharge line thermostat (TDL 2) are closed.

When the (CC2) contacts close, compressor (CPR2) starts.

Electromechanical Control Evaporator FanOperation (for Gas Units)

When the thermostat fan selection switch is set to the“Auto” position, the Ignition Module (IGN) energizes theindoor fan relay (F) approximately 1 second afterenergizing the compressor contactor coil (CC1) in thecooling mode. In the heating mode, the Ignition Module(IGN) energizes the indoor fan relay (F) coil approximately45 second after gas ignition. Closing indoor fan relay (F)coil starts the indoor fan motor (IDM).The (IGN) de-energizes the fan relay (F) approximately 80 seconds afterthe cooling requirement has been satisfied to enhance unitefficiency.

When the heating cycle is terminated, the indoor fan relay(F) coil is de-energized approximately 90 seconds after theheating requirement.

Table 23. Ignition module diagnostics

Steady lightModule is powered up, but no active call for heat.

Blinking at continuous steady rate

Active call for heat.

One blink Loss of communication.

Two blinksSystem lockout (failure to ignite, no spark, low/no gas pressure, etc.)

Three blinksPressure switch (no vent air flow, bad CBM, closed at initial call for heat). Auto reset.

Four blinksHigh limit (excessive heat in combustion chamber, low airflow). Auto reset.

Five blinksFlame sensed and gas valve not energized or flame sensed and no call for heat.

Six blinks

Flame rollout (CBM failure, incorrect gas pressure, incorrect primary air). Requires manual reset of the switch.

Seven blinksReliaTel module will communicate a heat fail diagnostic back to the RTRM.

RT-SVF55C-EN 19


When the thermostat fan selection switch is set to the“On”position, the (IGN) keeps the indoor fan relay coil (F)energized for continuous fan motor operation.

Electromechanical Evaporator FanOperation (for Cooling Only Units)

When the thermostat fan selection switch is set to the“Auto” position, the thermostat energizes the indoor fanrelay coil (F) to start the indoor fan motor (IDM).The fanrelay (F) de-energizes after the cooling requirement hasbeen satisfied. When the heating cycle is terminated, theindoor fan relay (F) coil is de-energized with heatercontactors.

When the thermostat fan selection switch is set to the“On”position, the thermostat keeps the indoor fan relay coil (F)energized for continuous fan motor operation.

Economizer Set-Up

Adjusting the minimum position potentiometer located onthe unit economizer actuator (ECA) sets the requiredamount of ventilation air.

Ambient temperature is controlling the economizing cycleby sensing the outside air dry bulb temperature. Table 22,p. 18 lists the selectable dry bulb values by potentiometersetting.

Electromechanical Control Cooling withan Economizer

The economizer is utilized to control the zone temperatureproviding the outside air conditions are suitable. Outsideair is drawn into the unit through modulating dampers.

When cooling is required and economizing is possible, theunit economizer actuator (ECA) opens the economizerdamper.The ECA continues to modulate the economizerdamper open/closed to keep the mixed air temperature inthe 50ºF to 55ºF range.

The thermostat will close theY2 contacts to turn oncontactor (CC1) if mechanical cooling is required.

If economizing is not possible, the ECA drives the damperto the minimum position setpoint when the indoor fanrelay (F) is energized and allows mechanical coolingoperation.

Electromechanical Control HeatingOperation (for Cooling Only Units)

When the system switch is set to the “Heat” position andthe zone temperature falls below the heating setpoint, thethermostat closesW1 contacts the first stage electric heatcontactor (AH or AH & CH) is energized. If the first stage ofelectric heat can not satisfy the heating requirement, thethermostat closes W2.When theW2 contacts close, the second stage electric heatcontactor (BH) is energized, if applicable.The thermostatcycles both the first and second stages of heat “On” and

“Off” as required to maintain the zone temperaturesetpoint.

Electromechanical Control HeatingOperation (for Gas Units)

When the system switch is set to the “Heat” position andthe zone temperature falls below the heating setpoint, theIgnition module (IGN) initiates a heat cycle.

Ignition Module Low, Medium andHigh Heat

Two-stage (IGN) runs self-check (including verification thatthe gas valve is de-energized). (IGN) checks the high-limitswitches (TC01 &TC02) for normally closed contacts, thepressure switch (PS) for normally open contacts, and theflame rollout (FR) switch for continuity. (IGN) energizesinducer blower on high speed to check pressure switchclosure.

If the pressure switch is closed, the inducer blower startsa 20 second pre-purge (15 seconds on high speed followedby 5 seconds on low speed).

If the pressure switch (PS) is still open, the inducer blowerwill continue to be energized on high speed until pressureswitch closure.

After pre-purge completes, the (IGN) energizes the firststage of the gas valve, initiates spark for 2 secondsminimum, 7 seconds maximum (ignition trial) and detectsflame and de-energizes spark. From this point, a fixed 45second indoor blower delay on timing starts.

After the indoor blower delay on is completed, the (IGN)energizes the indoor blower.The (IGN) enters a normaloperating loop where all inputs are continuouslymonitored. If the first stage of gas heat can not satisfy theheating requirement, the thermostat closesW2.The (IGN)energizes the second stage of the gas valve and the secondstage of inducer blower.

When the zone thermostat is satisfied, the (IGN) de-energizes the gas valve.The (IGN) senses loss of flame.The (IGN) initiates a 5 second inducer blower post purgeand 90 second indoor blower delay off at current speed.The (IGN) de-energizes the inducer blower at the end of thepost purge.The (IGN) de-energizes the indoor blower atthe end of the selected indoor blower delay off.

20 RT-SVF55C-EN


Drain Pan Condensate Overflow Switch(Optional)

The Condensate Overflow Switch (COF) is utilized toprevent water overflow from the drain pan.The floatswitch is installed on the corner lip of the drain pan.Whenthe condensate level reaches the trip point, the COF relayenergizes and opens the 24VAC control circuit whichdisables the unit. Once the 24VAC control circuit is opened,a delay timer will prevent unit start-up for three minutes.

Table 24. Ignition module diagnostics

Steady lightModule is powered up, but no active call for heat.

Blinking at continuous steady rate

Active call for heat.

One blink Loss of communication.

Two blinksSystem lockout (failure to ignite, no spark, low/no gas pressure, etc.)

Three blinksPressure switch (no vent air flow, bad CBM, closed at initial call for heat). Auto reset.

Four blinksHigh limit (excessive heat in combustion chamber, low airflow). Auto reset.

Five blinksFlame sensed and gas valve not energized or flame sensed and no call for heat.

Six blinks

Flame rollout (CBM failure, incorrect gas pressure, incorrect primary air). Requires manual reset of the switch.

Seven blinksW1& W2 swapped (electromechanical 3-10 tons units).

RT-SVF55C-EN 21

22 RT-SVF55C-EN

Pressure Curves

Figure 1. T/YSC090F Cooling cycle pressure curve

RT-SVF55C-EN 23

Subcooling Charging Chart

Figure 2. T/YSC090F subcooling charging chart

0.0

100.0

200.0

300.0

400.0

500.0

600.0

50 60 70 80 90 100 110 120 130

Liqu

id P

ress

ure

Leav

ing

OD

Coi

l, p

sig

Liquid Temperature Leaving OD Coil, °F

Remove charge

Add charge

The manufacturer optimizes the performance of homes and buildings around the world. A business of Ingersoll Rand,the leader in creating and sustaining safe, comfortable and energy efficient environments,the manufacturer offers abroad portfolio of advanced controls and HVAC systems, comprehensive building services, and parts. For moreinformation, visit www.IRCO.com.

The manufacturer has a policy of continuous product and product data improvement and reserves the right to change design and specifications without notice.

We are committed to using environmentally

conscious print practices that reduce waste.

Refrigerant Circuit

Figure 3. T/YSC090F refrigerant circuit

Compressor

Filter DrierAir

Air

TXV

Refrigerant Flow CoolingSystem 1

Service ValveHigh Pressure Control DLTS

Low Pressure Control

Service Valve

Service Valve

Mic

roch

anne

l

TopID COIL

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RT-SVF55C-EN 11 July 2014

Supersedes RT-SVF55C-EN (01 Feb 2014)

packaged rooftop air conditioners - precedent- cooling, … · 2017. 4. 27. · 6 rt-svf55c-en...

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