Table 11 - Cv 4 Or 6 Compressor Logic - Staging Table 27 - Suction Pressure Transducer Output - York eco2 050 Installation Operation & Maintenance

Service
controller called the MOD-UNT. The MOD-UNT then
communicates the pressures to the main unit control-
ler (Primary Unit Controller) via an N2 communica-
tion buss. Figure 51 shows the MOD UNT controller,
and Figure 52 il lus trates the connections between the
discharge pres sure transducer, the MOD-UNT, and the
Primary Unit Controller.
The Discharge Transducer has a range of 0 PSIG to 500
PSIG, with a linear output of 0 volts DC to 5 volts dc.
Table 26 illustrates the DC volt output from the trans-
duc er for a given discharge pressure.
Suction Pressure Transducer
The optional suction pressure transducer is located in
common suction line of the tandem compressors for each
refrigerant circuit. The purpose of this transducer is to
sense and convert the suction pressure to a DC voltage.
TABLE 27 – SUCTION PRESSURE TRANSDUCER OUTPUT
INPUT PRESSURE - PSIG
0
10
20
30
40
50
60
70
80
90
100
LOW AMBIENT OPTION –
CONDENSER FAN MO TOR VSD
The low ambient option for the unit includes a vari-
able speed drive (VSD) for the condenser fan motor.
The VSD is located in an enclosure directly beneath
the condenser fan coil. There will be one enclosure for
each VSD. The VSD is a non-programmable speciÞ c
ap pli ca tion VSD circuit board that drives the con dens er
fan motor based on a signal from the MOD-UNT (see
sec tion on Sequence of Operation).
124
SUCTION PRESSURE TRANSDUCER OUTPUT TABLE
OUTPUT VOLTAGE - VDC
1.00
1.20
1.40
1.60
1.80
2.00
2.20
2.40
2.60
2.80
3.00
The DC voltage is then sent to the unit con trol ler where
it can control head pressure (with optional low ambient
kit), provide compressor unloading, and display suction
pressure on the OptiLogic
ducer and wiring are factory installed. When ev er the
optional transducer package is supplied, the transducer
is wired to a factory supplied controller called the MOD-
UNT. The MOD-UNT then com mu ni cates the pressures
to the main unit controller (Primary Unit Controller) via
an N2 communication buss. Figure 52 il lus trates the
connections between the suction pressure trans duc er,
the MOD-UNT, and the Primary Unit Controller.
The Suction Transducer has a range of 0 PSIG to 200
PSIG, with a linear output of 0 volts DC to 5 volts DC.
Table 27 illustrates the DC volt output from the trans-
duc er for a given suction pressure.
INPUT PRESSURE - PSIG
110
120
130
140
150
160
170
180
190
200
The condenser fan motor is driven by the VSD based
on a variable 0 - 5VDC signal from the MOD – UNT.
This signal is based on the pressure transducer output
as compared to the preprogrammed "Discharge Pres sure
Control" setpoint (160 psig). The VSD outputs a 10 Hz
to 60 Hz to the condenser fan motor to maintain the "
Discharge Pressure Control" setpoint.
Fig. 53 illustrates the connections on the VSD board
(also refer to the unit wiring di a grams at the end of this
manual).
FORM 100.50-NOM1 (604)
display pan el. The trans-
TM
OUTPUT VOLTAGE - VDC
3.20
3.40
3.60
3.80
4.00
4.20
4.40
4.60
4.80
5.00
YORK INTERNATIONAL