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SYSTEM CALIBRATION, SERVICE SETPOINTS AND RESET PRO CE DURES
The chiller is supplied from the YORK Factory with all
factory mounted components fully calibrated. The fol-
low ing procedures are used to verify these cal i bra tions or
calibrate a component after it has been fi eld re placed.
Programmable Service Setpoints are used by the Pro gram
to control critical chiller operation. Also, some of these
Setpoints can be used to enable or disable cer tain features.
Although they have been entered at the YORK Factory,
they can be changed by a fi eld Service Tech ni cian that
has logged in at SERVICE access lev el. If the BRAM
battery backed memory device (U52) is fi eld replaced,
all of the programmed setpoints will be lost. They will
have to be re-entered into the new BRAM. Each of these
Setpoints is described below. Pro gram ming pro ce dures
and OptiView Control Cen ter Key pad operation required
in the pro ce dures be low are de tailed in YORK Operation
Manual 160.54-O1. In gen er al, the fol low ing procedure is
used to enter Setpoints in this sec tion:
1. Unless noted otherwise in procedures below, log
in at SERVICE access level using Access Code
1 3 8 0 .
2. Select the appropriate Display Screen.
3. Press the desired Setpoint key.
A dialog box appears, giving the minimum and
max i mum allowed values, Default value and pres-
ent value. The dialog box can be can celed at any
time by pressing the CANCEL (X) key.
4. If the dialog box begins with the word "Enter", use
the numeric keys to enter the desired value. Lead ing
zeroes are not necessary. Press the
a decimal point at the appropriate place. Press ing
the
▲
key displays the Default val ue. Press ing the
key clears the entry. The
▼
key and causes the entry point to move back one
space. If the dialog box begins with "Select"or "En-
able", use the
and
val ue. The
key decreases the value. The
in creas es the value.
5. Press the ENTER (✔) key. If the value is within
range, it is accepted and the dialog box dis ap pears.
The chiller will begin to operate based on the new
value. If out of range, the value is not accepted and
a message describing why it is not acceptable is
displayed momentarily.
Some Safety shutdowns will not permit the chiller to start
until a special reset procedure is performed. These reset
YORK INTERNATIONAL
SECTION 23
•
key to place
key is a back space
keys to select the de sired
key
procedures require SERVICE access level and should not
be performed by anyone other than a Ser vice Tech ni cian.
Each of these procedures is described below.
ELECTRO-MECHANICAL STARTER AP PLI CA -
TIONS
If the Compressor Motor is driven by an Electro-
Me chan i cal Starter, the OptiView Control Center is
equipped with a CM-2 Current Module along with
sup port ing com po nents Diode Bridge (DB) and Cal-
i bra tion Resistors (RES), as de scribed in a previous
chap ter of this book. The following procedures can be
used to verify the cal i bra tion and perform the calibra-
tion if necessary. In ad di tion to the calibration, Switch
S1 and Potentiometer R16 have to be set appropriately
on the CM-2 Module. If the CM-2 and/or RES are fi eld
re placed, fi eld cal i bra tion is necessary.
CM-2 Settings:
1. Place Switch S1 in the appropriate position per the
Starter type:
UP: Y-Delta or Auto-transformer Start er
Down: All others
2. Calculate LRA/FLA ratio by dividing the Motor
Lock Rotor Amps by the chiller Full Load Amps
(LRA/FLA = ratio) and then adjust Po ten ti om e ter
R16 to the ratio value.
Calibration Verifi cation:
1. At the Keypad, log in at SERVICE access lev el
us ing access code 1 3 8 0 .
2. Select MOTOR Screen and set Current Lim it and
Pulldown Demand Limit Setpoints to 100% FLA.
3. Run chiller. Read compressor motor current in
Phase A, B, and C using a clamp-on Am me ter.
Apply ammeter to highest Phase.
4. Select COMPRESSOR Screen.
5. Manually operate the Pre-rotation Vanes by press-
ing the OPEN and CLOSE Keypad keys as re quired
to achieve a motor current equiv a lent to 100% FLA
as indicated by the clamp-on Am me ter. The motor
current value on the Display should indicate 100%
FLA.
6. Manually operate the Pre-rotation Vanes by press-
ing the OPEN and CLOSE keys as required to
FORM 160.54-M1(503)
23
133
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