Installation and Maintenance Manual

Installation—Electrical
42 UV-SVN02C-EN
• 480V, 3-phase, 4-wire system: L1, L2, L3, and N
(neutral)
Note: T
he supply neutral wire must be connected to the
neutral terminal block.
Operational controls and an electric heating safety device
are factory mounted. The safety device is a high temp cut-
out which de-energizes electric heating elements through
the K1 safety contactor.
Heating Coils with Direct Expansion
Cooling
Wiring. A typical unit ventilator with DX coil includes an
outside air thermostat, a frost prevention thermostat and
a 24 V transformer for condensing unit control.
Wire sizing is the same as given for the thermostat wiring
in the condensing unit installation instructions, or may be
obtained from the nameplate. The condensing unit must
be controlled by the same room thermostat that also
controls the Unit Ventilator.
Split System Start-Up. After all piping and wiring has
been completed, follow the instructions provided with the
condensing unit for control testing and system start-up. If
sweat-type field-piped systems are being used, then
pressure testing, evacuation and refrigerant charging will
be required.
Two bulbs will also be shipped with a split system unit:
1. Frost stat bulb
2. TXV valve bulb
Both components are to be field installed. For complete
installation instructions and locations, refer to the tag
attached to the unit. See Figure 38, p. 42 for an example of
the installation tag.
Note: Depending on the controls package ordered with
the unit, not all installations will require mounting
the frost stat bulb.
WARNING
Hazardous Voltage!
Disconnect all electric power, including remote
disconnects before servicing. Follow proper lockout/
tagout procedures to ensure the power can not be
inadvertently energized. Failure to disconnect power
before servicing could result in death or serious injury.
Figure 38. Frost stat/TXV valve bulb installation tag
IMPORTANT:
INSTALLER MUST MOUNT THERMAL
EXPANSION VALVE BULB AND FROST
PROTECTION BULB (if suppled) TO
SUCTION LINE AFTER CONNECTION
OF FIELD REFRIGERANT PIPING
X39001939010A
12
3
6
93:00
4:00
8:00
9:00
X
X
MOUNT BULB IN
HORIZONTAL PLANE
RECOMMENDED
BULB PLACEMENT
UV-SVN02_-EN.book Page 42 Thursday, January 24, 2013 4:48 PM