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System Calibration
Calibration Verifi cation:
At the Keypad, login at SERVICE access level using
access code 1 3 8 0 .
1. Compressor Motor current display accuracy -
a. Run chiller.
b. Select COMPRESSOR Screen.
c. Use the Pre-rotation Vanes HOLD keypad key
to sta bi lize the Compressor Motor current.
d. Measure phase A, B and C Compressor Motor
cur rent with a clamp-on ammeter. Compare the
Ammeter values with displayed mo tor current
val ues. If displayed values are not within +5%
of Ammeter values, refer to Solid State Starter
Ser vice Manual 160.46-OM3.1 to trou ble shoot
Start er.
2. Start Current - Proper starting current is (45% x
Del ta locked Rotor amps).
a. Select COMPRESSOR Screen.
b. Start chiller and monitor Compressor Motor
start ing current in phase A, B and C on the
COMPRESSOR Screen.
Highest phase should be equiv a lent to (45% x
Del ta Locked rotor amps).
3. Overload -
a. Select COMPRESSOR Screen.
b. Run chiller and monitor Compressor Motor cur-
rent on the COMPRESSOR Screen.
c. Manually operate the Pre-rotation Vanes by
press ing the OPEN, CLOSE and HOLD keys,
as required, until the high est phase in di cates a
cur rent equivalent to 105% FLA.
The Display should indicate 105% and the 105%
LED on the Solid State Starter Logic Board
should illuminate when the 105% FLA val ue is
reached.
If the calibration verifi cation does not perform as above,
one or both of the following Calibration procedures will
have to be performed:
Calibration:
At the Keypad, log in at SERVICE access level using
access code 1 3 8 0.
1. Start Current -
a. Select COMPRESSOR Screen.
b. Loosen locking nut on Solid State Starter Log ic
Board Potentiometer R38.
c. Start chiller and monitor Compressor Motor
start ing current in Phase A, B and C on the
COM PRES SOR Screen.
136
d. While chiller is starting, adjust START CUR-
RENT potentiometer (R38) on Solid State Start er
Logic Board to achieve the proper start ing cur-
rent of (0.45 x Delta Locked rotor Amps) on the
high est phase. Turning R38 Clock wise in creas es
cur rent; Counterclockwise decreases current.
Mul ti ple starts could be required to achieve the
correct cal i bra tion. Tighten locking nut.
2. Overload -
a. Select COMPRESSOR Screen.
b. Run Chiller and monitor Compressor Motor
cur rent on the COMPRESSOR Screen.
c. Manually operate the Pre-rotation Vanes by
press ing the OPEN, CLOSE and HOLD key pad
keys, as required, until the highest phase indi-
cates a current equivalent to 105% FLA. Adjust
OVER LOAD potentiometer (R44) on Solid
State Starter Logic Board until the 105% FLA
LED il lu mi nates. Clockwise increases sig nal
level; Coun ter clock wise decreases signal level.
Tighten locking nut.
COMPRESSOR MOTOR VARIABLE SPEED DRIVE
APPLICATIONS
If the Compressor Motor is driven by the YORK Vari-
able Speed Drive (VSD), the OptiView Control Cen ter
is equipped with an Adaptive Capacity Control (ACC)
Board. Op er a tion of this board and overall VSD op er a tion
is de tailed in YORK Form 160.00-M1. There are two cal i -
bra tions that have to be performed; VSD Full Load Amps
and Pre-rotation Vanes position Po ten ti om e ter.
The VSD Full Load Amps value is the chiller full load
amps value as listed on the Sales Order. It is used by the
Program to initiate Current Limit at 100% and 104%
FLA.
The PRV Calibration establishes the voltage feed back
to the ACC Board at the fully closed and fully open
positions. Since the feedback between these extremes
is linear, the ACC Board will then know the actual PRV
position at all times. PRV position is required for the
speed control and surge prevention. If this procedure is
not performed or not performed successfully, variable
speed control is inhibited.
There are two setpoints that affect VSD operation; Surge
Margin and Stability Limit. They should nev er be changed
unless advised by YORK Factory Service. The Surge
Margin Setpoint allows the entire surge map to be ad just ed
up by a fi xed offset value. It is pro gram ma ble over the
range of 0 to 25.0 Hz. The Stability Lim it Setpoint de ter -
FORM 160.54-M1(503)
YORK INTERNATIONAL
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