CTV-PRB004-EN 39
Medium-Voltage Starter Types (2,300–6,600 Volts)
8. The S contacts open to open the autotransformer circuit.
9. The autotransformer is now connected as a series reactor with the motor.
10. Now, a secondT interlock and a second S interlock both close to energize the run contactor (2M).
11. The 2M contacts close to bypass the transformer and connect the compressor motor directly
to
the line.
Standard features
• Control-power transformer
• Primary and secondary current transformers (CTs)
• Potential transformers (PTs)
• Grounding provisions
• Bolted line-power connections
• Bolted load-side connections for remote starters
• Standard motor protection
Environmental specification
• Designed, developed, and tested in accordance with UL 347
• NEMA 1 enclosure as standard
• Operation from sea level to 6,000 ft (1,829 m)
• Operating ambient temperature range 32°F to 104°F (0°C to 40°C)
• Relative humidity, non-condensing 5% to 95%
• Non-operating ambient temperature range -40°F to 158°F (-40°C to 70°C)
• Voltage utilization range ±10%
Figure 31. Simplified autotransformer wiring diagram
LINE
VOLTAGE
AUTO-TRANSFORMER
OL
OL
OL
2M
1M
1M
1M
CPT
PR
PR
2M
2M
T
T
T
1M
1M
TRANSITION
START-
STOP
F
F
S
S
S
50%
80%
65%
100%
S
S
MOTOR
2M
CTV-PRB004.book Page 39 Sunday, December 18, 2011 6:39 PM
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