Electric Resistance Heater Assembly - IEC Vertical F*C Series Installation, Operation & Maintenance Manual

IEC Vertical F*C Series Fan Coils
INSTALLATION, OPERATION, & MAINTENANCE MANUAL
Figure 16: Motor Blower Deck Servicing
Coil
Coils may be cleaned by removing the motor/blower
assemblies and brushing the entering air face between
fins with a stiff brush. Brushing shall be followed by
cleaning with a vacuum cleaner. If a compressed air source
is available, the coil may also be cleaned by blowing air
through the coil fins from the leaving air face. This shall
again be followed by vacuuming. Units provided with the
proper type of air filters, replaced regularly, will require less
frequent coil cleaning.

Electric Resistance Heater Assembly

Electric resistance heaters typically require no normal
periodic maintenance when unit air filters are changed
properly. The operation and service life may be affected by
other conditions and equipment in the system. The two
most important operating conditions for an electric heater
are proper airflow and proper supply voltage. High supply
voltage and/or poorly distributed or insufficient airflow over
the element will result in element overheating and possible
limit switch openings.
This condition may result in the heater cycling on the high
limit thermal cutout. Sheath heaters have automatic reset
switches only. Open-strip heaters have an automatic reset
switch with a backup, high-limit thermal switch. Automatic
International Environmental Corporation • Vertical F*C Series Fan Coil Installation, Operation, & Maintenance Manual
20
reset limit switches are as the name implies, they reset
automatically after the heater has cooled down.
High-limit thermal switches must be replaced once the
circuit has been broken. The high-limit thermal cutout
device is a safety device only, and is not intended for
continuous operation. This device only operates when a
problem exists, and ANY condition that causes high-limit
cutout MUST be corrected immediately. High supply voltage
also causes excessive amperage draw and may trip the
circuit breaker or blow the fuses on the incoming power
supply.
After proper airflow and supply power are assured, regular
filter maintenance is important to provide clean air over
the heater. Dirt that is allowed to deposit on the heating
element will cause hot spots and eventual element burn
through. These hot spots will normally not be enough to
trip the high-limit thermal cut-out device, and may not be
evident until actual heater element failure.
Electrical Wiring and Controls
The electrical operation of each unit is determined by the
components and wiring of the unit. This may vary from unit
to unit. Consult the wiring diagram attached to the unit for
the actual type and number of controls provided on each
unit.
The integrity of all electrical connections should be verified
at least twice during the first year of operation. Afterwards,
all controls shall be inspected periodically for proper
operation. Some components may experience erratic
operation or failure due to age. Wall thermostats may also
become clogged with dust and lint, and shall be periodically
inspected and cleaned to provide reliable operation.
When replacing any components such as fuses, contactors,
or relays, use only the exact type, size and voltage
component as furnished from the factory. Any deviation
without factory authorization could result in personnel
injury or damage to the unit. This will also void all factory
warranties. Only factory supplied replacement parts
ensure that the warranty and agency status remain in
effect. All repair work shall be done in such a manner as
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