Operation - Chromalox CXH-A/B-03S Installation, Operation And Maintenance Instructions

6. Operation

General
1. The CXH-A/B unit heaters use a sealed water-glycol filled
heat exchanger. The electric immersion elements trans-
fer heat energy directly to the fluid generating a fluid/va-
por mixture which releases its heat energy to the finned
radiator as it rises and condenses 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.
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.
Startup
1. Prior to startup, ensure that heater has been properly in-
stalled per this manual and local requirements.
2. When starting up after long period of in-operation, en-
sure that proper maintenance procedures have been
performed. Not following preventative maintenance pro-
cedures can lead to potential dangerous operating con-
ditions.
3. Stand clear of front of heater to avoid possible injury.
Manual and Automatic Reset Thermal
Cutout
1. High temperature cutout(s) must never be bypassed
in control circuit. The factory must perform the re-
placement of the immersion heater or high temper-
ature cutout. The heat exchanger seal must not be
broken. Consult factory for service.
2. Resetting the manual cutout multiple times without re-
solving the cause of the tripping may allow the heater to
operate in an unsafe condition. Failure to investigate and
resolve a trip condition could result in personal injury or
property damage.
3. The automatic and manual reset limit controls are located
in the heating element hazardous location enclosure on
the heat exchanger which is covered by the sheet metal
housing attached to the side of the unit.
4. To gain access, remove the four sheet metal screws
holding the sheet metal cover in place and unthread the
cast aluminum enclosure lid.
5. The manual reset limit control device has a small reset
button protruding from the center of its back housing.
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 built in alarm pilot
lamps which will energize when abnormal conditions oc-
cur. Review troubleshooting section for information on
addressing these situations.
5. Do not operate in ambient temperatures exceeding 40°C
(104°F).
4. Unless fitted with the optional 3 position selector switch,
heater should immediately start once power is supplied.
5. In temperatures below -20°C, the fan may not begin ro-
tating for several seconds. This is normal as the motor
and heat exchanger must heat up the entire unit in order
for it to begin rotating.
6. Depress this button in to reset the control. Replace the
aluminum enclosure lid and sheet metal cover.
7. The automatic reset limit control does not require reset-
ting. If nuisance tripping occurs, consult maintenance
and troubleshooting sections. Do not try to remove or
replace.
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