York YVAA Installation Operation & Maintenance page 103

Form 201.47-ICOM1
Issue date: 17/11/2022
24 VAC power is applied to the 331-03478-xxx
microboard connector J12 and is then used to create the
various DC power sources required by the microboard
circuitry. If the chiller control is malfunctioning, the
power supply test points should be measured to deter-
mine the status of the microboard.
Power supply test points
TP1 GND (Measure TP2, TP3, TP4 and TP5 in
reference to this Test Point).
TP2 +3.3 V [3.2 VDC to 3.4 VDC] provides power to
the processors.
TP3 +5 V [4.8 VDC to 5.2 VDC] power communica-
tion ports 2,3 and 4 and analog sensors.
TP4 +12 V [11.64 VDC to 12.36 VDC] powers the dis-
play and backlight and is regulated to become the +5 V.
TP5 +15 V [11.3 VDC to 16.6 VDC] powers the analog
outputs to the EEV valves.
Configuration jumpers
The same configuration jumpers that existed on the
02478 are provided on the 03478.
JP4 Remote Temp Reset jumper position Pins 1 to 2
(left) = 4 mA to 20 mA, Pins 2 to 3 (right) = 0 VDC to
10 VDC.
JP5 Remote Current Limit jumper position Pins 1 to 2
(left) = 4 mA to 20 mA, Pins 2 to 3 (right) = 0 VDC to
10 VDC.
JP6 Remote Sound Limit jumper position (Pins 1 to 2
(left) = 4mA to 20 mA, Pins 2 to 3 (right) = 0 VDC to
10 VDC.
JOHNSON CONTROLS
SECTION 7 - OPERATION
103
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