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periodically using a brush and
vacuum cleaner, taking care not
to dislodge the factory applied
balancing weights on the blower
wheel blades. Clean the blower
at every inspection. Any blower
or motor that is not properly
maintained will not be covered
under the manufacturer’s
warranty.
Electric heating element Finned
tubular type heaters generally
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
heater will result in the element
overheating. This condition may
result in the heater cycling on
the primary automatic high limit
thermal cutout. If the temperature
becomes too high, the secondary
high limit thermal cutout may be
activated, breaking the circuit and
leaving the unit non-operational.
The primary automatic thermal
cutout will reset automatically
after the heater has cooled
down, allowing the unit to run
again without intervening.
The secondary thermal cutout
is a safety device only, is
not intended for continuous
operation and will need to be
replaced before the unit will
operate again. With proper unit
application and operation, the
primary high limit thermal cutout
will not operate. This device only
operates when there is a problem
and ANY condition that causes the
high limit cutout to operate 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 verified, regular filter
maintenance is important to provide
clean air over the heater. A dirty filter
will inhibit the proper airflow, leading
to high temperature situations.
Improper filtration will also lead to
dirt being deposited on the heating
element, causing hot spots and
eventual element burn through.
These hot spots will generally not
be enough to cause the high limit
switches to trip and may not be
evident until the element actually
fails. Dirt deposited on the element
will also cause unwanted odors in the
air-conditioned space as the foreign
material is burned off.
Electrical wiring & controls
T
he electrical operation of each unit
is determined by the components
and wiring of the unit. This may vary
from unit to unit. Refer to the wiring
diagram located in a zip-lock plastic
bag on the air block-off plate of each
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
should be inspected regularly for
proper operation. Some components
may experience erratic operation or
failure due to age. Thermostats may
become clogged with dust and lint,
and should be periodically inspected
and cleaned to provide reliable
operation.
When replacing any electrical
components such as fuses,
contactors, relays or transformers,
use only the exact type, size
and voltage component as
furnished from the factory. Any
deviation from this could result
in personnel injury or damage
to the unit. This will also void
the manufacturer’s warranty. All
repair work should be done in
such a way as to maintain the
equipment in compliance with
governing local and national
codes, ordinances and safety
testing agency listings.
Valves and piping
No formal maintenance is
required on the valve package
components other than a visual
inspection for possible leaks
during normal periodic unit
maintenance. Strainers, when
included, should be checked
regularly for build-up and rinsed
as needed. In the event that a
valve should need replacement,
the same precautions taken
during the initial installation
to protect the valve package
from excessive heat should be
implemented during replacement
Throwaway filters
These types of filters should
be replaced on a regular basis.
The time interval between
replacement is dependent upon
the environment in which the
unit is operating and should
be set established based on
regular inspection of the filter.
Record the time interval in the
maintenance log for future
reference. Refer to the product
catalog for the recommended
filter size. If the replacement
filters are not purchased from
the factory, the same type and
size filters should be obtained.
MERV9 or higher pleated media
or extended surface filters
should not be used without
consent from the factory due
to the high air pressure drops
Maintenance
Maintenance
