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Electrical Inspection – Service & Distribution June 2005 Glacier Valley Elementary School Condition Survey Report Page 147 of 178 0911 Distribution Panels & Switchgear – Equipment, conduit, feeders, and grounding The building’s Main Distribution Panel (MDP) is located in a dedicated room off the boiler room. The unit is a ‘Power Switchboard’ by Square D and is the originally installed equipment. It is fed from the utility padmount transformer outside via underground conduits and internal current transformers (for revenue metering) to the main disconnects on the panel front. The MDP is rated for 1200 amperes, 120/208 volts, threephase, fourwire. Billing records from AEL&P for the past two and a half years indicate a peak demand of 116 kilowatts in January of this year. This represents a peak load of just over 322 amperes, well within the capacity of the MDP and the service conductors. As installed the MDP is configured without a single main service disconnect. This is permissible by the National Electrical Code as long as no more than six individual disconnects are operated to remove all power from the facility. That is the case with this unit, as five breakers (Lighting Main, Power Main, Panel K, Panels F and G, and Panel X) will disable all the power. The Panel Schedules appear correct, but the definite breakers needed to disconnect the service are not accurately depicted. Again, this is not necessarily a code violation, just a suggested operational clarification. The MDP, circuit breakers and conductors are all in good condition – aging but with significant service life remaining. Remaining life expectancy: 20 years.

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Page 1: Electrical Inspection – Service & Distribution · Electrical Inspection – Service & Distribution June 2005 Glacier Valley Elementary School Condition Survey Report Page 147 of

Electrical Inspection – Service & Distribution 

June 2005  Glacier Valley Elementary School Condition Survey Report  Page 147 of 178 

0911 Distribution Panels & Switchgear – Equipment, conduit, feeders, and grounding 

The building’s Main Distribution Panel (MDP) is located in a dedicated room off the boiler room.  The unit is a ‘Power Switchboard’ by Square D and is the originally installed equipment.  It is fed from the utility padmount transformer outside via underground conduits and internal current transformers (for revenue metering) to the main disconnects on the panel front.  The MDP is rated for 1200 amperes, 120/208 volts, three­phase, four­wire.  Billing records from AEL&P for the past two and a half years indicate a peak demand of 116 kilowatts in January of this year.  This represents a peak load of just over 322 amperes, well within the capacity of the MDP and the service conductors. 

As installed the MDP is configured without a single main service disconnect.  This is permissible by the National Electrical Code as long as no more than six individual disconnects are operated to remove all power from the facility.  That is the case with this unit, as five breakers (Lighting Main, Power Main, Panel K, Panels F and G, and Panel X) will disable all the power.  The Panel Schedules appear correct, but the definite breakers needed to disconnect the service are not accurately depicted.  Again, this is not necessarily a code violation, just a suggested operational clarification. 

The MDP, circuit breakers and conductors are all in good condition – aging but with significant service life remaining. 

Remaining life expectancy:  20 years.

Page 2: Electrical Inspection – Service & Distribution · Electrical Inspection – Service & Distribution June 2005 Glacier Valley Elementary School Condition Survey Report Page 147 of

Electrical Inspection – Service & Distribution 

June 2005  Glacier Valley Elementary School Condition Survey Report  Page 148 of 178 

Deficiency 

0911­1:  Poor Marking of Main Service Disconnect(s) The correct service disconnect circuit breakers are not specifically noted.  There are 19 breakers in the MDP, five will disconnect the power, but they are not noted. 

Deficiency category:  Functional – F. 

Remedy Recommend providing laminated labels for each circuit breaker along with specific instructions for the service disconnect procedure.  One suggestion is to color code the labels to denote the correct breakers. 

Estimated Construction Cost:  $2,000.

Page 3: Electrical Inspection – Service & Distribution · Electrical Inspection – Service & Distribution June 2005 Glacier Valley Elementary School Condition Survey Report Page 147 of

Electrical Inspection – Service & Distribution 

June 2005  Glacier Valley Elementary School Condition Survey Report  Page 149 of 178 

0912 Panels & Motor Control Centers – Equipment, conduit, feeders, and grounding 

The building panelboards are well distributed, moderately filled, most with spares and accurately labeled for the most part.  The original panels are all vintage Square D units while Panels F and G are more recent with accompanying Transient Voltage Surge Suppressors.  The recent panels are used to feed the new receptacles and plugmold for computers in each classroom.  Most of the panelboards do not have a ground bus nor are any grounding conductors run with circuit conductors.  Typically the raceway system is used for a ground return path. 

Originally, each classroom had a single duplex receptacle mounted on opposing interior walls.  Most have been replaced with plugmold containing any number of single and/or duplex receptacles.  It is likely that circuiting limitations have been exceeded with these configurations.  The newer panels F and G provide additional circuits to each classroom. 

Although very good quality, the original panelboards throughout the building are 40 years old and are starting to approach the practical end of their useful life.  Most of the school loads are fed from these older panels with most of the wiring from the same era (1960’s). 

Remaining life expectancy:  10 years.

Page 4: Electrical Inspection – Service & Distribution · Electrical Inspection – Service & Distribution June 2005 Glacier Valley Elementary School Condition Survey Report Page 147 of

Electrical Inspection – Service & Distribution 

June 2005  Glacier Valley Elementary School Condition Survey Report  Page 150 of 178 

Deficiency 

0912­1:  No Grounding Bus in Panelboards Individual equipment grounding conductors are creatively terminated in various panelboards. 

Deficiency category:  Code (NEC) – C. 

Remedy Provide proper grounding buses and connections in each panelboard with equipment grounding conductors terminating within. 

Estimated Construction Cost:  $10,600.

Page 5: Electrical Inspection – Service & Distribution · Electrical Inspection – Service & Distribution June 2005 Glacier Valley Elementary School Condition Survey Report Page 147 of

Electrical Inspection – Service & Distribution 

June 2005  Glacier Valley Elementary School Condition Survey Report  Page 151 of 178 

Deficiency 

0912­2:  No Clear Access in Front of Panelboards Equipment is stored in front of panelboards limiting access and working clearance. 

Deficiency category:  Code (NEC) – C. 

Remedy Relocate equipment to proper storage area. 

Estimated Construction Cost:  $0.

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Electrical Inspection – Service & Distribution 

June 2005  Glacier Valley Elementary School Condition Survey Report  Page 152 of 178 

Deficiency 

0912­3:  Overloaded Circuits 

Existing (original) panelboards and circuits appear to be overloaded and approaching end of useful life. 

Deficiency category:  Renewal & Replacement – RR. 

Remedy 

Provide new distribution panelboards and circuit breakers to replace the existing original units.  Provide all new feeder conductors in the existing raceways to feed the replacement panelboards. 

Estimated Construction Cost:  $56,200.