REFLECTED WAVE TRAP- A Quantum Leap in Motor Protection

The Problem: Over-Voltage Spikes @ Motor Terminals (Reflected Waves)

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0V Failure Threshold

(>1000 Volts)

• Significant motor failures (insulation failure) caused by reflective wave spikes • High dV/dt on PWM pulse creates over-voltage spikes at motor terminals.• Occurs with cable lengths >50 feet (between drives and motor).• Per NEMA MGI Part 30 and VDE 530, motors rated for 600V or less withstand a peak voltage of only 1000V.• Existing solutions (A-B Terminator, TCI series filters) have performance limitations.

MDrive

Reflected wave at motor terminals

The Solution: Reflected Wave Trap (RWT)

Without RWT

With RWT

Patented RWT installed at motor terminals: prevent motor damage/failures

1. One Size Fits All!

Only one model required for• 208 to 480 Volt applications• any H.P. motor• any drive/motor manufacturer

2. Two Enclosure Styles

Benefits of the Cutler-Hammer RWT

• NEMA 1 • NEMA 4X; Class I, Div 2 for hazardous environments

3. Superior Clamping

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With RWT

480 Volt Application

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Without RWT

Benefits of the Cutler-Hammer RWT (continued)

4. Status Indicator Light

• Not available with competitor models • Status indicator turns “OFF” if unit fails

5. Cost Effective, Easy to Install

Benefits of the Cutler-Hammer RWT (continued)

• Easy installation for retrofit and new systems • Mount within 25 feet of motor• Lower energy losses

6. The “Coolest” Solution • A-B normal operating temperature: 125 - 220°C (safety hazard, limits cable length, higher power losses) • C-H Reflected Wave Trap normal operating temperature: < 60°C for NEMA1; <90°C for NEMA 4X

Reflected Wave Solutions:Comparison of Heat Sink Temperatures

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A-B @216°C

C-H @ 90°C

Surface Temperature (degree’s Celsius)

Benefits of the Cutler-Hammer RWT (continued)

0100200300400500600700800900

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480 Volt Drive: Reflected Wave ProtectionTechnology Comparison

competitor RWT (40 degree ambient) RWT (25 degree ambient)

Extended Protection with RWT

0 6 12Drive Speed (kHz)

CompetitorPerformance

• Higher carrier frequency:operates up to 12 kHz (compared to 2 to 6 kHz for competitor design)• Flexibility of operation: enables longer cable lengths between drive and motor•Eliminates cable degradation due to over voltage

7. Longer Cable Lengths, Faster Carrier Freq.

Benefits of the Cutler-Hammer RWT (continued)

R C N e t w o r k s R W T

O p e r a t i n gF r e q u e n c y

T y p ic a l ly < 6 k H z O v e r 1 2 k H z

P o w e r L o s s / H e a t i n g C o n s t a n t c u r r e n td r a w

C u r r e n t d r a w o n lyw h e n p e a k e x is t s

C a b l e L e n g t h L im i t e d d u e t o d r iv elo a d in g

L e s s c u r r e n t m a k e slo n g e r le n g t h sp o s s ib le

P e a k V o l t a g e I n c r e a s e s w i t hc a b le le n g t h

C o n s t a n t f o r c a b lele n g t h

The RWT is patented by Cutler-Hammer

Why RWT Technology?

Overview of Reflected Wave Solutions

Advantages Disadvantages

SERIES DEVICES Line Reactor LC Filters

Cost advantage on 1-10 HP

motors Can be used if motor is in

hazardous environment

voltage and torque reduction must be sized to motor hp higher cost for large motors complexity and losses

PARALLEL DEVICES(motor termination) Line Terminating

Impedance (RC filterby A-B)

Clipping device(RWT)

no voltage drop device can be used universally

on all sizes of drives

better peak voltage suppression device can be used universally

on all sizes of drives Cost effective (>15 HP)

high power losses carrier frequency limited not always suitable for small drives not applicable on deep wells

not applicable on deep wells

Additional Information on RWT & Drive Applications

RWT brochure (B.037F.01.S.E)Specification Guide (TD.37F.02.T.E)Commercial Article on RWT (AP.037F.01.T.E.)Installation & Operating Guide (TD-37F.01.T.E)Industry Articles (contact Surge Protection product line - attn Satendra Prasad)

Application assistance: Cutler-Hammer Drive Sales Managers

Stock/Price: Vista registered (stocked in Spartensburg)

Industrial Surge Protection Example