Install Instructions

2-525.2
5
START-UP PROCEDURE / MAINTENANCE
Figure 5.1 - Exposed Side of Electric Unit Heater
3
2
1
1. Heating elements
2. Adjustable air deflectors
3. Overheat control
IMPORTANT
Start-up and adjustment procedures should be performed by
a qualified service agency.
Prior to Operation
Although this unit has been inspected and tested at the factory,
the following procedures should be performed to assure proper
on-site operation:
1. Check fan clearance. Fan should not contact casing when
spun by hand.
2. Check all electrical connections to be sure they are secure,
and in accordance with the wiring diagram.
3. Check firmness of unit suspension. Tighten all fasteners,
if necessary.
4. Make sure fuses are installed in units that require them.
Safety Devices
The overheat control, mounted on the left inner side panel (See
Figure 5.1), will interrupt power to the unit contactor in the event
of overheating. It is a single-pole, single-throw switch, with an
automatic reset. The switch will permit the motor to continue
operation and cool the heater while power to the elements
is interrupted. This overheat control should operate only
when something is seriously wrong with the unit. When
this control operates, correct the difficulty immediately or
serious and permanent damage may result.
The motor for the circulating air fan has internal thermal overload
protection. If for any reason the motor overheats, the thermal
protector will shut it off. The motor will restart automatically when
it has cooled.
Initial Start-Up
1. Set thermostat above room temperature.
2. Turn on power to the unit.
3. Adjust the air deflector blades for desired heat distribution.
All horizontal blades should be kept open a minimum of 45°
as measured from vertical.
4. Run the unit through several cycles by raising and lowering
the thermostat setting to assure proper sequence of
operation.
Operating Sequence
The operation of Modine electric unit heaters is governed by
an electrical contactor which is controlled by a thermostat.
The contactor completes the electric circuit to the heating
elements when the thermostat “calls” for heat. The fan motor is
also activated when the thermostat “calls” for heat. When the
thermostat is satisfied, the fan motor stops and the contactor
opens the circuit to the heating elements.
Routine Unit Maintenance
Under average conditions, it is recommended that unit heaters
be serviced at least once a year and checked out prior to the
heating season. In excessively dirty atmospheres, service
should be performed more often.
1. Disconnect power supply to the unit before performing
any of the following maintenance or inspection
procedures.
2. Open hinged door at the bottom rear of the unit by loosening
the retaining capscrew. Lowering the door will reveal the
unit contactors, fuses, transformers, and their electrical
connections. Check all components and wiring inside the unit
for firm connections and/or wear.
3. Tighten fan guard and motor bracket. Check fan for proper
clearance, free rotation, and firm connection to motor shaft.
Clean fan blade with detergent or compressed air.
4. Fan motor is permanently lubricated for normal operation.
Under severe conditions, lubricate with non-detergent SAE 20
motor oil.
5. Routine cleaning of the unit casing and louvers is
recommended to remove dirt, grease, or corrosive
substances that may damage the finish. Rusted or corroded
spots on the louvers or casing should be sanded and
repainted. To remove, push louvers against retaining coil
spring and pull out at opposite tapered end.
6. Check entire electrical system before every heating season.