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FORM 160.54-M1
ISSUE DATE: 10/25/2019
This board provides Overload, Power Fault, Fault Cur-
rent, Phase Rotation/Loss, and Half Phase Protection
for the Compressor Motor. It also receives SCR High
Temp and Trigger Out Of Lock (OOL) shutdown sig-
nals from the Starter Trigger Board. Finally, it provides
analog voltages representing Compressor Motor Cur-
rent, Power Line Voltage, Current Limit commands
and a Starter Model code to the microboard.
The contacts of Logic Board relay K1 (identified as
CM contacts on the OptiView Control Center wiring
diagram) are interfaced into the Motor Controller initi-
ated shutdown circuit that is located between OptiView
Control Center TB6-53 and I/O Board TB1-16 (See
Figure 36 on page 103 and Figure 55 on page 131).
They are also connected as a Digital Input to I/O Board
J2-1. Relay K1 is normally energized, maintaining
its contacts in a closed position. Whenever the Logic
Board initiates a chiller shutdown, it de-energizes K1,
opening its contacts. This interrupts the circuit to I/O
Board RUN relay coil 1R (K18), de-energizing it and
causing the Starter to de-energize. Simultaneously, the
microboard reads the opening of these contacts via I/O
Board J2-1, initiates a System Coastdown and displays
the appropriate message as described below.
When the Logic Board detects an Overload condi-
tion, relay K1 contacts open and the Overload LED
illuminates. MOTOR CONTROLLER – CONTACTS
OPEN is displayed. The contacts remain open and the
LED remains illuminated until manually reset with the
Logic Board's S1 RESET switch. After S1 is pressed,
the chiller can be restarted.
When a Power Fault, Fault Current or Half Phase con-
dition is detected, relay K1 contacts open for 1 second
and then close. The Power Fault LED illuminates and
will remain illuminated until manually reset with the
S1 RESET switch. POWER FAULT is displayed. At
the completion of System Coastdown, the chiller will
automatically restart.
When a Power Line Phase Rotation/Loss or Trigger
Board Out of Lock (OOL) condition is detected, relay
K1 contacts open and remain open for as long as the
condition exists. If the contacts remain open for more
than 3 seconds, MOTOR CONTROLLER – CON-
TACTS OPEN is displayed; if less than 3 seconds,
POWER FAULT is displayed. The respective Phase
Rotation/Loss or Trigger Board Out of Lock (OOL)
LED illuminates and remains illuminated until manu-
ally reset with the S1 RESET switch. The chiller will
automatically restart when the contacts close.
JOHNSON CONTROLS
The Starter Trigger Board monitors the Starter's Sili-
con Controlled Rectifier (SCR) Heat sink temperature.
Whenever the heat sink temperature increases to 212°F,
the Trigger Board signals the Logic Board. MOTOR
CONTROLLER – CONTACTS OPEN is displayed.
The Logic Board illuminates the High Temp LED and
opens relay K1 contacts. The LED remains illuminated
and the contacts remain open until the temperature de-
creases to less than 110°F and manually reset with the
Logic Board's S1 RESET switch. After S1 is pressed,
the chiller can be restarted. In routine operation, each
time the chiller is shutdown for any reason, it is pre-
vented from restarting until the heat sink temperature
decreases to less then 110°F. While it is waiting for
the temperature to decrease to this threshold, the HIGH
TEMP LED is illuminated, relay K1 contacts are open,
and MOTOR CONTROLLER – CONTACTS OPEN
is displayed. When the temperature is below 110°F,
K1 contacts will open, the LED is extinguished, MO-
TOR CONTROLLER – CONTACTS OPEN message
is cleared and the chiller will automatically restart.
The Multiplexer (MUX) is an electronic switch with
8 inputs and 1 output. The address applied to it de-
termines the position of the switch and therefore the
output. Under Program control, the microboard se-
quentially addresses MUX channels 0 through 7. The
voltage output of each channel is listed in the Table
11 on page 140. Channel 0 is an analog voltage that
represents the Starter Model and Power Line Voltage
Voltmeter Scale. The Program uses this value to limit
the Full Load Amps setpoint range to the maximum
allowed value for the Starter size. This value also de-
termines the Line Voltage Display Range and Motor
Current Display Range. Channel 1 is a current limit
command that forces the microprocessor to perform
Pre-rotation Vanes inhibit and closure at the 100% and
104% FLA. This command is in addition to the mi-
croprocessor's Software Current Limit feature that's
based on a calculation comparing the highest current
phase to the programmed Full Load Amp setpoint to
arrive at an FLA percentage. Channels 2 though 4 are
analog voltages representing Phase C, B and A Power
Line Voltages. Channels 5 through 7 are analog volt-
ages representing Phase A, B and C Compressor Motor
Current. The addresses are +12 VDC for logic high (1);
less than 1 VDC for logic low (0).
The Logic Board MUX address inputs, along with the
respective outputs are shown in Table 11 on page 140.
JCI COMPANY CONFIDENTIAL
SECTION 13 - SOLID STATE STARTERS
13
139
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