GE MM200 Instruction Manual page 41

CHAPTER 2: INSTALLATION
MM200 MOTOR MANAGEMENT SYSTEM – INSTRUCTION MANUAL
When a start A (low speed) control is received, the pre-contactor relay (if any) is picked up
for the set pre-contactor time. When the pre-contactor timer times out, relay1 picks up
and seals-in, picking up contactor L, which starts the motor in low speed. When a start B
(high speed) control is received, the relay1 drops out, and contactor L drops out. When
contactor L Off status is received, the relay2 picks up and seals-in, picking up contactor H,
which starts the motor in high speed. Should a start A (low speed) control be received when
relay2 is picked up, relay2 is drops out, and contactor H drops out. When contactor H Off
status is received, the starter waits for the set transfer time to allow the motor to slow.
When the transfer time timer times out, the relay1 picks up and seals-in, picking up
contactor L, which starts the motor in low speed. When a stop control is received, the
relays 1 and 2 drop out, contactors L and H drop out, and the motor stops. If the
SPEED START BLOCK setting is "Enabled", this starter will not allow a start B (high speed)
control unless already running at low speed.
The pre-contactor is omitted on forced starts (for example, External Start). Forced starts are
not supervised by this starter transfer timer – any external starting circuit must itself
respect high to low speed transition restrictions and starting in high speed restrictions.
STARTER TYPES
HIGH
2–23