York YCIV Series, Installation Operation & Maintenance

Page: 230 / 326

JOHNSON CONTROLS
230
FORM 201.23-NM2
ISSUE DATE: 09/25/2020
SECTION 8 - MICROPANEL
Power Supplies and LEDs
The 03478 has LEDs to indicate various states of op-
eration of the microboard.
STATUS – Flashes every ½ second to indicate that the
base board processor is running its program.
POWER – On solid indicates that the base board +12
V and +5 V power supplies are operational.
TX1 – Red LED flashes when transmitting data out
Port 1 TB3 (Future native communications BAS port)
RX1 – Green LED flashes when receiving data in Port
1 TB3 (Future native communications BAS port)
TX2 – Red LED that flashes when transmitting data
out Port 2 (E-Link TB2 or printer TB1)
RX2 – Green LED that flashes when receiving data in
Port 2 (E-Link TB2 or printer TB1)
VSD_TX – Red LED that flashes when transmitting
data out Port 3 to the VSD Logic board
VSD_RX – Green LED that flashes when receiving
data in Port 3 from the VSD Logic board
FIGURE 60 - MICROBOARD 331-03478-XXX
TP10 +24 V TP5 +15 V
TP4 +12 V
TP1 GND
U18 VSD
RS-485 Driver
VSD RX
VSD TX
Port 2
RX2
TX2
RS-232
to Printer
Power LED
Status
LED
TP3
+5V
TP2
+3.3V
SD
Card
Power
LED
U5 RTC/
BRAM
JP4 JP5 JP6 Remote
Setpoint Jumpers
Port 2
RS-485 to
E-Link
U26 Port 1
RS-485 Driver
U23 Port 2
RS-485 Driver
Port 1
Future
Native
BAS
LD19331
24 VAC power is applied to the 331-03478-xxx mi-
croboard 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.