YORK INTERNATIONAL
72
FORM 160.54-M1(503)
This board pro vides Overload, Power Fault, Fault
Cur rent, Phase Ro ta tion/Loss, and Half Phase Pro-
tec tion for the Com pres sor Motor. It also receives SCR
High Temp and Trig ger Out Of Lock (OOL) shutdown
sig nals from the Start er Trig ger Board. Fi nal ly, it pro-
vides an a log volt ag es rep re sent ing Com pres sor Motor
Cur rent, Pow er Line Volt age, Current Limit com mands
and a Start er Model code to the Microboard.
The contacts of Logic Board relay K1 (identifi ed as
“CM” contacts on the OptiView Con trol Center wiring
diagram) are interfaced into the Motor Controller ini-
ti at ed shut down circuit that is located between OptiView
Con trol Center TB6-53 and I/O Board TB1-16 (ref. Fig.
16 and 37). They are also connected as a digital input to
I/O Board J2-1. Relay K1 is normally en er gized, main-
tain ing its con tacts in a closed position. When ev er the
Logic Board initiates a chiller shut down, it de-en er giz es
K1, open ing its con tacts. This interrupts the cir cuit to I/O
Board RUN re lay coil 1R (K18), de-en er giz ing it and
causing the Start er to de-en er gize. Si mul ta neous ly, the
Microboard reads the opening of these con tacts via I/O
Board J2-1, ini tiates a SYSTEM COASTDOWN and
dis plays the ap pro pri ate message as described below.
When the Logic Board detects an Overload con di tion,
Re lay K1 contacts open and the Over load LED il lu -
mi nates. “MOTOR CON TROL LER – CONTACTS
OPEN” is dis played. The contacts remain open and the
LED re mains il lu mi nat ed 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
condition is detected, Relay K1 con tacts open for 1 sec-
ond and then close. The Power Fault LED illuminates
and will re main illuminated until manually reset with
the S1 RESET switch. POWER FAULT is dis played.
At the com ple tion of SYSTEM COASTDOWN, the
chill er will au to mat i cal ly restart.
When a Power line Phase Rotation/Loss or Trigger Board
Out of Lock (OOL) con di tion is detected, Relay K1 con-
tacts open and remain open for as long as the con di tion ex-
ists. If the contacts remain open for more than 3 sec onds,
MOTOR CONTROLLER – CON TACTS OPEN is
displayed; if less than 3 seconds, POWER FAULT is
dis played. The respective Ph. Rot/Loss or Trig. OOL
LED illuminates and re mains il lu mi nat ed until manu-
ally reset with the S1 RE SET switch. The chiller will
au to mat i cal ly restart when the contacts close.
The Starter Trigger Board monitors the Starter’s Sil-
i con Controlled Rectifi er (SCR) heatsink temperature.
Whenever the heatsink temperature increases to 212ºF,
the Trigger Board signals the Logic Board. MO TOR
CON TROL LER – CONTACTS OPEN is dis played.
The Log ic Board illuminates the High Temp LED and
opens Re lay K1 contacts. The LED remains il lu mi nat ed
and the con tacts remain open until the tem per a ture de-
creas es to less than 110ºF and manually reset with the
Logic Board’s S1 RESET switch. After S1 is pressed,
the chiller can be restarted. In routine op er a tion, each
time the chiller is shutdown for any rea son, it is pre-
vent ed from restarting until the heatsink tem per a ture
de creas es to less then 110ºF. While it is waiting for the
tem per a ture to decrease to this thresh old, the HIGH
TEMP LED is illuminated, Relay K1 contacts are open,
and MOTOR CON TROL LER – CONTACTS OPEN
is dis played. When the temperature is below 110ºF, K1
contacts will open, the LED is ex tin guished, MO TOR
CONTROLLER – CONTACTS OPEN mes sage is
cleared and the chiller will au to mat i cal ly re start.
The Multiplexer (MUX) is an electronic switch with 8
inputs and 1 output. The address applied to it de ter mines
the po si tion of the switch and therefore the out put. Under
Program control, the Microboard se quen tial ly addresses
MUX channels 0 through 7. The volt age output of each
channel is listed in the table below. Channel 0 is an
analog voltage that represents the Start er 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 determines the Line Volt age display range and
Motor current display range. Channel 1 is a cur rent limit
command that forces the Micro to perform Pre-rotation
vanes inhibit and clo sure at the 100% and 104% FLA.
This command is in ad di tion to the Micro’s software cur-
rent limit feature that’s based on a calculation comparing
the highest cur rent phase to the programmed Full Load
Amp Setpoint to arrive at an FLA Percentage. Channels
2 though 4 are an a log voltages representing Phase C,
B and A
Solid State Starters
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