Step 3 — Make Electrical Connections — Refer to unit nameplate for required supply voltage, fan and heater amperage and required circuit ampacity. Refer to unit wire dia- gram for unit and field wiring. Make sure all electrical connec- tions are in accordance with unit wiring diagram and all appli- cable codes.
The fan motor(s) should never be controlled by any wiring or device other than the factory-supplied switch or thermostat/ switch combination unless prior factory authorization is obtained. Fan motor(s) may be temporarily wired for use during construction only with prior factory approval and only in strict accordance with the instructions issued at that time.
Floor cabinet type units have factory-wired integral fan switches. Connect power wires to leads in unit junction box per unit wiring diagram. On the other units, install remote fan switch according to job drawings. Hook up switch and power wiring per unit wiring diagram.
Install optional, wall-mounted thermostat per instructions shipped with thermostat. Connect as shown on unit wiring diagram.
Units with factory-supplied and factory-installed aquastats may be shipped with the aquastats mounted on a coil stub-out. If this is the case, remove the aquastat before installing valve package. When reinstalling aquastats, consult the factory- piping diagram in the submittal for proper location. If the valve package is field-supplied, the aquastat must be installed in a location where it will sense the water temperature regardless of the control valve position. A bleed bypass may be required to guarantee proper aquastat operation. The aquastat bypass line allows a small amount of water to flow from the supply to the return piping when the control valve is closed.
NOTE: The aquastat must be able to sense whether the flowing water is being chilled or heated and switches a contact closed to provide automatic summer or winter changeover for the system. When a two-pipe cooling/heating system with optional auxiliary electric heat is desired, an additional aquastat is required.
All field wiring must be in accordance with governing codes and ordinances. Any modification of unit wiring without factory authorization will invalidate all factory warranties and nullify any agency listings.
IMPORTANT: Wiring diagrams shown depict typical control functions. Refer to unit wiring label for specific functions.
Units may be equipped with line voltage controls or
24 VAC control systems. The following descriptions are for line voltage controls only. For 24 v control operating sequence, refer to thermostat operating instructions.
STANDARD WIRING PACKAGES
Manual Fan Control — On all vertical cabinet units, the stan- dard fan-speed switch is furnished unit-mounted and wired. See Fig. 50. On all vertical furred-in units and all horizontal units, the switch is shipped separately on a decorative wall plate for field mounting and wiring.
The standard switch has LOW, MEDIUM, HIGH and OFF positions plus an auxiliary contact to energize thermostats, valves, dampers, etc.
NOTE: Wiring diagrams are for 120-v power supply. If other voltages for heaters or controls are specified, wiring may differ from that shown.
NOTES:
1.Motors are thermally protected.
2.Use copper conductors only.
3.See unit nameplate for power supply. Provided disconnect means and overload protection as required.
4.Unit-mounted thermostats are not recommended for fan control because of poor temperature sensing. Fan control not available on 42VC,VE lowboy units.
Fig. 50 — Manual Fan Control
