FORM 150.40-NM20
45
YORK INTERNATIONAL
be ignored by the Micro Logic Board. Closure longer than
11 seconds will be treated as 11 seconds.
The contact closure corresponds to a positive offset
(rise) from the Setpoint on the panel. I sec. = +0° offset
and 11 sec. = +15° or offset = 1.5 (time closed – 1 sec.).
For example: A Setpoint of 51° on the panel and a con-
tact closure of 4.33 sec. will result in an offset of +5°.
This raises the RWT Setpoint to 56°F.
To maintain a remote setpoint, the EMS Pulse Width
Modulation input (terminals 11 and 12) on the Digital
Input Board must be refreshed every 30 minutes or less
(20 minutes is recommended). In other words, to main-
tain the 56°F RWT setpoint, the contacts between ter-
minals 11 and 12 must be closed for a period of 4.33
seconds every 20 minutes. If this is not refreshed at
least every 30 minutes, the Micro Logic Board will take
this as a signal to change the RWT setpoint back to the
original setpoint of 51° on the Control Panel.
(YCHA120, 150, 175, & 200)
EXTERNAL SYSTEM MONITORING AND
DIAGNOSTICS (OPTIONAL)
RS 232 (or equivalent) SERIAL COMMUNICATION
OUTPUT PORT
This port on the bottom right of the Logic Board (J6)
allows service personnel to obtain a printout of unit con-
“OPTIONAL” REMOTE UNLOADING AND DEMAND
LIMITING
A forced unload of the system, independent of water
temperature demand, can be accomplished by closing
a dry contact connected between terminals 9 & 10 of
the optional Digital Input Board. This control feature
forces turn-off of the lag compressor. Note: J9 must
also be placed IN or Switch 4 must be in the ON posi-
tion on the Micro Logic Board. See Fig. 20 and 21.
ANNUNCIATION ALARM CONTACTS (OPTIONAL)
YORK can supply alarm contacts which will de-energize to
function as a warning if unit malfunction occurs. A 28 volt
external alarm circuit (by others) must be wired into the
YORK supplied alarm circuit. If the alarm circuit is applied
to chillers used for critical duty (such as process duty, or
cooling other critical equipment) and the alarm circuit should
fail to function, YORK will not be liable for damages. Any
inductive devices (relays) wired into the Alarm circuitry must
be suppressed. Use P/N 031-00808B suppressor.
ditions at any time. To make use of this option, contact
YORK Service or Marketing for recommended printers.
A printout can be requested by pressing the “Press To
Print” pushbutton on the Control Panel. This allows ser-
vice personnel or the customer to obtain system pa-
rameters on a periodic basis.*
A print example is shown below.
YORK RECIPROCATING CHILLER
MICROCOMPUTER CONTROL CENTER
SYSTEM STATUS
NO SYSTEM FAULTS
RETURN WATER TEMPERATURE 55.4 DEG F
LEAVING WATER TEMPERATURE 44.0 DEG F
SYSTEM 1 OIL TEMPERATURE 131.9 DEG F
SYSTEM 2 OIL TEMPERATURE 130.8 DEG F
LOW WATER TEMP CUTOUT 36.0 DEG F
TEMPERATURE SETPOINT 54.0 DEG F
OUTSIDE AIR TEMPERATURE 090.2 DEG F
LOW AMBIENT TEMP CUTOUT 35.0 DEG F
SYSTEM 1 MOTOR CURRENT 087 %FLA
SYSTEM 1 SUCTION PRESSURE 066 PSIG
SYSTEM 1 OIL PRESSURE 044 PSID
SYSTEM 1 DISCHARGE PRESSURE 197 PSIG
SYSTEM 2 MOTOR CURRENT 087 %FLA
SYSTEM 2 SUCTION PRESSURE 059 PSIG
SYSTEM 2 OIL PRESSURE 051 PSID
SYSTEM 2 DISCHARGE PRESSURE 191 PSIG
LOW SUCTION PRESSURE CUTOUT 044 PSIG
TEMPERATURE CONTROL RANGE 54.0 DEG F
TO 48.0 DEG F
SYSTEM 1 LIQUID LINE SOL NO
SYSTEM 2 LIQUID LINE SOL NO
SYSTEM 1 LOADED NO
SYSTEM 2 LOADED NO
RUN PERMISSIVE YES
* Once the printout is obtained, the printer should be disconnected from the panel at J6.
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