14
ABB
CONTROL SCHEME:
ADVAC™ circuit breakers are available with two control packages. The standard package (see Appendix D) includes
charge, close, and open functions, and 4a and 4b auxiliary contacts for customer use. The optional package (see
Appendix D) adds to the standard package five ”a” and four “b” auxiliary contacts for customer use as well as an
optional second open coil and/or under voltage (UV) open/trip device if required. Refer to wiring diagrams in Appendix
D and Figure 3: Sequence of Operation.
1. Initial State
a. Closing Spring Discharged (33LSa Open/33LSb Closed)
b. Breaker Open (52a Open/52b Closed)
2. Upon available control power
a. Motor Disconnect Switch ON
b. Secondary engaged
c. Motor charges through 33LSb
3. Closing spring charged
a. 33LSa closes
b. 33LSb opens (removing control power to motor)
c. Breaker ready to close
4. Electrical control pulse sent to close circuit
a. Current energizes Close Coil 52X (Close Coil is not rated for continuous duty)
• Coil rotates half shaft and closes breaker
– 52a closes – 52b opens
• Coil de-energizes with release of signal and as 52b opens
b. Current energizes 52TC (Trip Coil is not rated for continuous duty)
• 52TCa closes
• 52TCb opens
c. Closing Spring Discharges
• 33LSa closes
• 33LSb opens
d. Closing Spring charges
• 33LSa closes
• 33LSb opens (removing control power to motor)
• Breaker ready to perform O-C-O operation
MECHANISM AND OPERATION
Courtesy of NationalSwitchgear.com
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