Aprilaire 1953 & 1972 - Manual (Page 9)

9
3A Fuse
Ground
Yellow (2)
NOT USED
Ballast
Lamp Socket
Red (2)
Blue (2)
White
Black
Green Green
Black
120VAC to
277VAC
Power Source
White
Interlock switches
(not provided)
recommended for
all access panel
doors
FIGURE 7 – Model 1972 Wiring Diagram
90-754
INSTALL LAMP
1. Remove Lamp from shipping tube. Use ceramic ends of Lamp when handling – do not touch the glass tube of Lamp.
Use alcohol to remove any dirt and/or fingerprints from the Lamp.
2. Snap the Lamp into the two Lamp Brackets.
3. Attach the Lamp Socket to the Lamp.
4. It is recommended that safety interlock switches (not provided) be installed on any access panel door
within view of the UV lamp.
5. Return all panel doors on the rooftop unit to their closed position.
6. Place three WARNING labels (included) on the rooftop unit: there are two for access panels and one to be placed
near the main disconnect switch.
7. Turn on the power to the rooftop unit.
MAKE ELECTRICAL CONNECTIONS
1. Verify power to the HVAC equipment is shut off. Determine where the power for the unit will come from. The units can use
any voltage from 120 VAC up to 277 VAC (single phase), 60 Hz. The ballast automatically adjusts to whatever voltage is supplied in
that range. The units must be wired such that the disconnect switch of the air handler is also the disconnect switch
for the UV lamp. Additionally, to prevent accidental exposure to UV germicidal light, it is recommended that safety
interlock switches (not provided) be installed on any access panel door within view of the UV lamp. See Figure 7 for
Model 1972 wiring diagram.
2. Run wiring from the power source through conduit, if used, and into the Lamp.
3. Shield non-metallic components (such as electrical wires and fan belts) that receive direct or reflected UV radiation
with aluminum tape, sheet metal, or conduit.