York AFFINITY YAFT026 Installation Manual page 18

AFFINITY & AFFINITY ADVANCED SINGLE & DUAL CAPACITY SERIES INSTALLATION MANUAL
Electrical Information cont.
Variable Speed Flow Center cont.
Two Pump Variable Speed Flow Center
If a variable speed two pump flow center is used, the flow center will come with four red and two green wires for the high
voltage wiring. The second set of (2) red and (1) green wires is provided for installation flexibility. The variable speed pump
MUST be powered at all times and therefore MUST be wired to the "L" side of electrical system or damage to the pump will
occur (pump cannot be powered from "T" side of compressor contactor). The UPMXL 25-124 pump has screw terminals for
the high voltage connection. Connect the red HIGH VOLTAGE wires to L1 and L2 on the AXB, connect the green GROUND
wire to the ground lug, as shown in figure 20. The low voltage wiring (PMW) will turn the pump(s) ON and OFF. Follow all
electrical and local codes for wiring.
The variable speed UPMXL 25-124 pump also requires a low voltage signal to operate properly, if the low voltage wires
aren't connected or the signal isn't present the pump will run at 100%. Route the low voltage harness connected to the right
hand pump to the AXB screw terminals on P2 and P3 connectors. Route the low voltage harness connected to the left hand
pump to the AXB screw terminals on P2 and P3 connector per figure 19. The black wire on the left hand pump will have a
label on it that reads "DO NO CONNECT THIS WIRE. ONLY ONE VS PUMP FEEDBACK SIGNAL CAN BE CONNECTED TO
AXB BOARD".
Both the low and high voltage harnesses are labeled. The pump will be automatically cycled as required either by the unit
or by a signal from another unit sharing the same flow center. Pumps are protected by circuit breakers as shown on the unit
schematic.
NOTE: Both pumps will speed up and slow down together.
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