York YPAL 050 User Manual

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164
JOHNSON CONTROLS
FORM 100.50-NOM6 (1207)
Service
24 VAC power is supplied to the compressor protection 
module for compressor 2A from wire 443 at terminal 
C30 of the P12 connector.  The binary input back to the 
Unit Controller from the compressor protection module 
is wire 442 at terminal C30 of the P12 connector.
24 VAC power is supplied to the compressor protection 
module for compressor 2B from wire 445 at terminal 
C40 of the P12 connector.  The binary input back to the 
Unit Controller from the compressor protection module 
is wire 444 at terminal C40 of the P12 connector.
Low Pressure Cutout Alarm (09, 10, 11, 12)
Since tandem compressors are used there is a single low 
pressure switch for system 1 and one for system 2.  If 
the low pressure switch opens both of the compressors 
for that system will be turned off.  If the low pressure 
switch for system 1, (compressors 1A, 1B), opens it will 
generate both a 09 and 10 alarm code.  Likewise if the 
low pressure switch opens for system 2, (compressors 
2A, 2B), opens it will generate both an 11 and 12 alarm 
code.  
The low pressure switch opens at 50 PSIG and closes 
at 71 PSIG.  In order to generate a low pressure lockout 
the high pressure switch must open three times within 
a 2 hour window.
During the start up of the compressor system the low 
pressure switch input is ignored for 30 seconds.  After 
the 30 second delay if the low pressure switch circuit 
opens for 5 seconds the Unit Controller will turn off 
both compressors for the system.
24 VAC power is supplied to the system 1 low pressure 
switch circuit from wire 395 at terminal LPS1 of the P15 
connector.  The binary input back to the Unit Controller 
from the low pressure switch is wire 396 at terminal 
LPS1 of the P15 connector.  The above input is then 
jumpered to terminal LPS2 of the P15 connector.
24 VAC power is supplied to the system 2 low pressure 
switch circuit from wire 433 at terminal LPS3 of the P16 
connector.  The binary input back to the Unit Controller 
from the low pressure switch is wire 434 at terminal 
LPS3 of the P16 connector.  The above input is then 
jumpered to terminal LPS4 of the P16 connector.
Limit Switch Alarms (13, 14, 15)
The control monitors the limit switch status for each of 
the heating sections installed.  If the limit switch circuit 
opens the control de-energizes the heat section output 
for the section with the open limit circuit and energizes 
the indoor blower output.  The supply fan performs a 
Fan Delay Off when the limit re-closes.  
In order to generate a limit lockout the limit switch must 
open three times within a 2-hour window.
The limit input for heat section 1 is located at terminal 
LIM1 wire 507 of the P10 connector.  The limit input 
for heat section 2 is located at terminal LIM2 wire 522 
of the P10 connector.  The limit input for heat section 
3 is located at terminal LIM3 wire 533 of the P10 
connector.
Gas Heating Alarms (16, 17, 18)
The Unit Controller monitors the output to the gas valve.  
If the Unit Controller is calling for the operation of the 
heat stage and voltage is not present after 5 continuous 
minutes it will generate an alarm.
If the Unit Controller is not calling for the operation of 
the heat stage and voltage is present at the gas valve for 
5 continuous minutes it will generate an alarm and lock 
on the supply fan.  If the input goes away the control 
will revert to normal operation.
The gas valve input for heat section 1 is located at 
terminal GV1 wire 510 of the P10 connector.  The gas 
valve input for heat section 2 is located at terminal GV2 
wire 525 of the P10 connector.  The gas valve input for 
heat section 3 is located at terminal GV3 wire 536 of 
the P10 connector.
Space Temperature Sensor Alarm (19)
This alarm indicates the space temperature input is 
either open or shorted.  The display will show a value 
of –40.0° F.  The space temperature input is at ST and 
GND of the P6 connector.  To trouble shoot compare the 
resistance of the input to the temperature in the space 
using Table 8-1.