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YORK INTERNATIONAL
FORM 150.63-NM1
11
1
wire must be field supplied (QUABBIN 930421-2 or
equivalent 2 conductor with shield and drain wire - 20
AWG 300 V 60 °C - polyethylene insulation UV resis-
tant). Field wiring is connected to pins 3, 6, and 9 of J6
on the microboard. Refer to Figure 8 and unit wiring
diagram.
ZONE THERMOSTATS
Field supplied thermostats or dry contacts must be field
wired when operating the unit in Suction Pressure
Control Mode. The System 1 zone thermostat is field
wired at CTB1 terminals 13 to 14. On two system units
(YCUL0046 - YCUL0090) System 2 zone thermostat
is field wired to CTB1 terminals 13 to 16. CTB 1 ter-
minal is located in the control panel. Refer to Figure 5
and unit wiring diagram.
See Air Proving Switch/Remote Start-
Stop Contacts.
Suction Pressure control cannot be used unless the
optional suction transducers are installed on the unit
(standard on YCUL0076 - YCUL0090).
Suction Temperature Sensors (optional)
This is a field installed option that provides individual
displays of suction line temperature for each system at
the condensing unit. This option performs no control
function, but simply provides the suction line tempera-
ture for each refrigerant system as measured at the con-
densing unit.
On the microboard, the connections are field wired to
J5, pins 7, 12, & 1 for System 1; J5, pins 8,13 & 2 for
System 2. Refer to Figure 9 and unit wiring diagram.
The sensors should be attached to the suction line with
copper straps, and heat conducting compound should
be used to ensure good heat transfer.
Air Proving Switch/Remote Start-Stop Contacts
The air proving switch is field wired to CTB1 termi-
nals 13- to 14 to prevent operation of the refrigerant
circuit when the supply air blower is not operating.
If separate evaporator blowers are used with respect to
each refrigerant system in the condensing unit, then two
air proving must be wired in series across CTB1 termi-
nals 13 - 14 (one for each evaporator blower). Refer to
Figure 5 and unit wiring diagram.
When using Zone Thermostats in Suction Pressure con-
trol mode, the air proving switch(es) should be wired
in series with the respective Zone Thermostats.
Remote Start/Stop Contacts
To remotely start and stop the condensing unit, dry con-
tacts can be wired in series with the air proving switch
and CTB1 - terminals 13 to 14. Refer to Figure 5 and
unit wiring diagram.
Remote Emergency Cutoff
Immediate shutdown of the condensing unit can be ac-
complished by opening a field installed dry contact to
break the electrical circuit between terminals 5 to L on
terminal block CTB2. CTB2 is located in the power
panel. The unit is shipped with a factory jumper in-
stalled between terminals 5 to L, which must be removed
if emergency shutdown contacts are installed. Refer to
Figure 6 and unit wiring diagram.
Evaporator Blower Start Contacts
For constant fan operation: Terminal block CTB2 - ter-
minals 23 to 24, are normally open contacts that can be
used to switch field supplied power to provide a start
signal to the evaporator blower contactor. Refer to Fig-
ure 6 and unit wiring diagram.
Compressor Run Contacts
Contacts are available to monitor “Compressor Run”
status. Normally-open auxiliary contacts from each
compressor contactor are wired in parallel with CTB2
- terminals 25 to 26 for system 1, and CTB2 - terminals
27 to 28 for system 2 (YCUL0046 - YCUL0090). Re-
fer to Figure 6 and unit wiring diagram.
Alarm Status Contacts
Normally-open contacts are available for each refrig-
erant system. These normally-open contacts close when
the system is functioning normally. The respective con-
tacts will open when the unit is shut down on a unit
Summary of Contents for MILLENNIUM YCUL0016SC
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