MAINTENANCE
ELECTRIC SHOCK HAZARD. Disconnect all power
before installing or servicing heater. Failure to do so
could result in personal injury or property damage.
Heater must be installed by a qualified person in accor-
dance with the National Electrical Code, NFPA 70.
A. To remove Heating Element –
1.
Remove terminal cover screws and terminal cover.
2.
Disconnect heating element from electrical leads at both ends.
3.
Remove screws from porcelain terminal blocks.
4.
Remove element support clips and secondary insulating
bushings.
5.
Lift element out of heater.
B. To Install Element —
Observe instructions for removing element and proceed in
reverse fashion. Be sure to replace secondary insulating bushings.
C. Care of Reflectors —
Reflectors should be cleaned periodically. A mild soap and
water solution or fine cleaning powder is best, although more
drastic means may be required if reflectors are badly soiled by
chemical or other deposits. The reflector is aluminum. DO
NOT use alkali cleaners since alkalies will dull reflector. Mild
non-alkaline cleaners, such as used for scouring kitchen sinks,
may be used. Reflectors are replaceable and may be purchased
from Chromalox.
4
OPERATION
FIRE/EXPLOSION HAZARD. This heater is not
intended for use in hazardous atmospheres where
flammable vapors, gases, liquids or other com-
bustible atmospheres are present as defined in the
National Electrical Code. Failure to comply can
result in personal injury or property damage.
Before energizing this heater:
1. Be sure
all electrical connections are tightly made. Hold ter-
minal with pliers when tightening screw.
2. Be sure
that all conductors are properly insulated, and that they
will not chafe at the heater wire entrance due to expansion and
contraction of the heating element.
3. Be sure
that all terminal covers have been properly replaced,
and that secondary insulation bushings have not been omitted.
A. Controlling Radiant Intensity —
Standard Radiant Heaters
are built to operate at approximately 40 watts per sq. inch on
the element sheath. When it is desired to reduce radiant inten-
sity, one or more of the following methods may be used.
i. INPUT CONTROLLERS.
These motor-driven cycling
devices can be used to vary heater output capacity from 4
to 100%.They are usually connected in holding coil circuit
of magnetic contactors. See Chromalox Radiant Heater
Manual for further information regarding Input Controllers
and Contactors.
ii. SOLID STATE POWER CONTROLLERS.
For best
non-contact control of radiant heat, a Chromalox SCR
Power Controller with manual potentiometer setting is rec-
ommended. Truly proportional output of from 0-100% can
be easily dialed-in to suit the particular product or process
requirements. The panels are pre-engineered, prepackaged
assemblies in an enclosure with circuit disconnect provided
and ready for installation.
B. Maximum Ambient Temperatures –
Chromalox Radiant Heaters are not recommended for applica-
tions in ambient temperature exceeding 450˚F. Higher ambient
temperatures mean shorter heater life.
Maximum work temperature in a given time depends on sever-
al factors: Reflectivity of work, specific heat of work, mass of
work, kW input and losses from oven, and time of exposure.
As work temperature increases, the work loses heat by radia-
tion and by convection to the surrounding ambient. Although it
is a general principle of Radiant Heater application that work
temperature conventionally exceeds ambient temperature, in
cases where extremely high work temperatures are desired, it is
necessary to enclose the heaters in order to increase the ambi-
ent. If evaporation of a liquid is desired as a result of increas-
ing work temperature, it is necessary to provide ventilation air
in order to carry away the evaporated liquid. Under carefully
engineered circumstances, a maximum work temperature of
600˚F may be attained.
