9600 Service Manual - gmecorp-usa.com

10 Interlocks / Stator
STATOR START
The Technique Processor PCB initiates the stator circuit by commanding the Analog
Interface PCB PIO U38 pin 20 & 23 to go high.
The high out of PIO U38-20 passes through buffer U45 pins 15 & 5, turning on transistor
Q3, causing the STAT_RUN signal to go low. This low passes through the Motherboard,
energizing relay K1 and illuminating LED DS1 on the Power Motor Relay PCB.
The high out of PIO U38-23 passes through buffer U45 pins 13 & 7, turning on transistor
Q7, causing the STATSTRT signal to go low. This low passes through the Motherboard,
energizing relay K2 and illuminating LED DS2 on the Power Motor Relay PCB.
This applies 115VAC to the stator motor through relay K1 contacts 5 & 6, relay K2
contacts 5 & 6, current sense transformer T1 and circuit breaker CB2. The 115VAC is
applied to the stator motor for two seconds, starting the stator and bringing it up to speed.
STATOR RUN
After the initial two second start sequence, the Technique Processor PCB commands the
Analog Interface PCB PIO U38-23 low. This low passes through buffer U45 pins
13 & 7, turning off transistor Q7, causing the STATSTRT signal to go high. This high
passes through the Motherboard, de-energizing relay K2 and turning off LED DS2 on the
Power Motor Relay PCB.
Relay K1 on the Power Motor Relay PCB is still energized at this time, allowing 115VAC
to pass through contacts 5 & 6 to the stator transformer T3. (See figure 4) Stator
transformer T3 steps the 115VAC down to 40VAC. This 40VAC is applied to the stator
motor through the de-energized relay K2 contacts 7 & 6, current sense transformer T1 and
circuit breaker CB2. The 40VAC is applied to the stator motor continuously, keeping the
stator spinning at approximately 3500 RPM.