Digital Outputs; Fig. 20 - Microboard Relay Contact Architecture - York YCAL Series Installation Operation & Maintenance

SECTION 9 - SERVICE AND TROUBLESHOOTING
The suction transducers have a range from 0 psig to
400 psig (27.58 barg). The output will be linear from
0.5 VDC to 4.5 VDC over the 400 psig (27.58 barg)
range. Following is a formula that can be used to verify
the voltage output of the transducer. All voltage read-
ings are in reference to ground (unit case).
V = (Pressure in psig x 0.01) + .5
V = (Pressure in BARG x 0.145) + .5
where V = dc voltage input to microprocessor
Pressure = pressure sensed by transducer
Following are the microboard connections for the Suc-
tion Transducer:
System 1 Suction Transducer
J7-5 = +5 VDC regulated supply to transducer.
J7-10 = VDC input signal to the microboard.
See the formula above for voltage readings that cor-
respond to specific suction pressures.
J7-9 = +5 VDC return
J7-1 = drain (shield connection = 0 VDC)
System 2 Suction Transducer
J9-5 = +5 VDC regulated supply to transducer.
J9-10 = VDC input signal to the microboard.
See the formula above for voltage readings that cor-
respond to specific suction pressures.
J9-9 = +5 VDC return
J9-1 = drain (shield connection = 0 VDC)
152
or

Digital Outputs

Refer to the unit wiring diagram and Fig. 20. The digi-
tal outputs are located on TB-7, TB-8, TB-9 and TB-
10 of the microboard. ALL OUTPUTS ARE 120VAC
with the exception of TB8-6 to TB8-7 which are the
contacts that can be used for a remote evaporator pump
start signal. The voltage applied to either of these ter-
minals would be determined by field wiring.
Each output is controlled by the microprocessor by
switching 120 VAC to the respective output connection
energizing contactors, evaporator heater, and solenoids
according to the operating sequence.
120VAC is supplied to the I/O board via connections
at TB7-1, TB7-6, TB10-1, TB10-6, TB8-1, and TB9-1.
Fig. 20 illustrates the relay contact architecture on the
microboard.
TB7
TB7
TB10
TB10
TB8
FIG. 20 – MICROBOARD RELAY CONTACT
ARCHITECTURE
FORM 150.66-NM3
ISSUE DATE: 09/25/2020
SYS 1
TB7-2
COMP 1
TB7-3 LLSV 1
SYS 1
TB7-4
COMP 2
SYS 1
TB7-5
COMP 3
SYS 1
TB7-7
HGSV
SYS 1
TB7-8
FAN 2
SYS 1
TB7-9
FAN 1
SYS 1
TB7-10
FAN 3
SYS 2
TB10-2
COMPR 1 (4)
TB10-3 LLSV 2
SYS 2
TB10-4
COMPR 2 (5)
SYS 2
TB10-5
COMPR 3 (6)
SYS 2
TB10-7
HGSV
TB10-8
SYS 2
TB10-9
FAN 2
SYS 2
TB10-10
FAN 4
TB8-6
EVAP
PUMP
TB8-7
HEAT EXCH
TB8-2
HEATER
LD12722
JOHNSON CONTROLS