WARNING!
Always disconnect unit heater from
power supply before attempting to
service, clean, or disassemble any
component from the unit. Failure to
do so may result in injury or death
due to electrical shock.
Electrical Circuitry
Inspect the control panel wiring once
each year to ensure that the insulation
is intact, and that all connections are
tight. Be sure to examine all heater
and relay contacts as well; if the
contacts appear badly pitted or
burned, replace the contactor/relay.
Note: To protect electrical circuits
during operation, use only the correct
size of over current protection; see
Table 2.
Cleaning
Clean the unit casing, fan and motor
on an annual basis. (A dirty motor
may run hot and will eventually be
damaged internally.) Clean and
repaint any rust spots on the casing.
Lubrication
All unit heaters with ratings of up to 20
Kw are equipped with permanently
lubricated fan motors, so only
occasional cleaning is required. Unit
heaters with ratings above 20 Kw
have fan motors factory-lubricated to
provide 5 years of continuous service,
or 10 years of intermittent operation.
If lubrication is desired, remove the oil
access plug on the back of the unit at
the motor intake grille. Then, open the
oil cap and add SAE No. 10
non-detergent electric motor oil.
Replace the cap and plug.
Note: Except in emergencies, do not
open the air disconnect while the
heater is in operation. Any power
interrupt during normal heater
operation will prevent the fan from
running; residual heat remaining in the
unit may cause the thermal cutouts to
open.
Maintenance
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UHEC-IM-7A
