Operation; Maintenance And Repair - Chromalox CXHA-03 Installation And Operation Instructions Manual

Operation

EXPLOSION HAZARD. Heater should not be operated
in ambient temperature higher than 40°C (104°F) or
in atmospheres corrosive to the heater itself.
1. The CXH-A unit heaters use a sealed water-glycol filled
heat exchanger. The electric immersion elements transfer
heat energy directly to the fluid generating a fluid/vapor
mixture which releases its heat energy to the finned ra-
diator as it rises and recondenses back to the bottom
reservoir to be reheated. This cycle will continue as long
as fan forced air is available on the finned structure to
remove the heat to the airstream.

Maintenance and Repair

Maintenance and repair MUST be performed by qualified personnel only.
EXPLOSION/ELECTRIC SHOCK HAZARD. Disconnect
all power before opening enclosure covers or servic-
ing heater. Failure to comply could result in personal
injury or property damage.
1. Periodically inspect all electrical connections and termi-
nals to avoid electrical wiring difficulties. Inspect all wir-
ing for frayed or worn insulation.
2. Periodically and before each heating season, clean the
finned heat exchanger and fan inlet with compresses
air, vacuum, or water jet. Be sure all electrical covers are
tightly closed.
3. If heat output seems to be low, check amperage draw on
each element. Compare measured values to the correct
currents as listed on the unit nameplate.
4. The thermally protected fan motor is permanently lubri-
cated and sealed. No field servicing is required or should
be attempted. Replace only with a factory supplied iden-
tical motor. Failure to do so will void the factory warranty
and may expose the user to risk of ignition of hazardous
atmospheres.
5. Check fan blade to be sure that set screws are tight and
there are no cracks or looseness in the blades. Use fac-
tory supplied replacement blade only.
6. Check for any sign of leaking from the heat exchanger.
Too little fluid will cause the high temperature cutout(s) to
trip or cycle. Periodically inspect the heater for leaks by
visual examination using a flashlight. Look for evidence
of fluid dunning down the face of the heat exchanger
from the top center. Look for evidence of fluid inside the
lower terminal enclosure and look for any fluid that may
have dripped or pooled in the sheet metal case. If evi-
dence of fluid leaking from the heat exchanger is found,
the unit should be removed from service and the cause
investigated. The heat exchanger is a sealed unit and can
only be serviced by returning to the factory.
7. The sealed heat exchanger contains a glycol/water solu-
tion of propylene glycol. Ethylene glycol is supplied for
arctic duty conditions only. Avoid contact with skin and
eyes. If ingestion should occur, seek medical attention
2. The finned structure of the heat exchanger must be kept
clean and free of accumulated dust and dirt. The cabi-
net front panel is easily removed providing access to the
heater core for periodic cleaning.
3. Unit should not be operated with louvers fully closed.
Mechanical stops are incorporated into the design of the
cabinet to limit the degree of closure. Do not force the
louvers beyond these stops.
4. If specified, units are supplied with a built in alarm pilot
lamp which will energize if the high temperature cutout(s)
has a been activated. During unit startup, the lamp will
flash on momentarily to verify its operation.
immediately. In case of eyes or skin contact, wash affect-
ed areas with large amounts of water. The MSDS (Mate-
rial Safety Data Sheet) for these materials is available
upon request.
I. REPLACING THE HEAT EXCHANGER
BURN HAZARD. Be sure heat exchanger and fluid
has been allowed to cool to 110°F before proceed-
ing.
1. Detach the cabinet front by removing screws from all
sides of unit and pulling cover forward off cabinet shell.
Detach bottom panel by removing two screws on each
side and two screws in the rear. Remove the electrical
control enclosure lid. Disconnect the heater and high limit
wires from the electrical control enclosure. Loosen elec-
trical conduit union located between the heater housing
and the electrical control enclosure. Support the lower
end of the heat exchanger and loosen the three hex head
bolts which hold it to the sheet metal. Lower the heat
exchanger away from the sheet metal. Reverse the above
procedure when installing a new heat exchanger.
II. RESETTING OPTIONAL MANUAL RESET HIGH
TEMPERATURE CUTOUT
EXPLOSION HAZARD. Be sure that all enclosure
covers are replaced and tightly closed before re-en-
ergizing unit after servicing electrical components.
High temperature cutout(s) must never be bypassed
in control circuit.
The factory must perform the replacement of the
immersion heater or high temperature cutout. The
heat exchanger seal must not be broken. Consult
factory for service.
Resetting the cutout multiple times without resolv-
ing the cause of the tripping may allow the heater
to operate in an unsafe condition. Failure to inves-
tigate and resolve a trip condition could result in
personal injury or property damage.
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