Chromalox PG421-1 - Manual (Page 2)

ELECTRIC SHOCK HAZARD. Disconnect all power
before installing or servicing heater. Failure to do
so could result in personal injury or property dam-
age. Heater must be installed or serviced by a
qualified person in accordance with the National
Electrical Code, NFPA 70.
1. Clamps — Heaters are mounted by means of the mounting
clamp and 3 /
8
” bolt assembly which is used as shown in Fig. 2.
Clamp assembly may be attached to heater by sliding over end
or by snapping over top of extruded frame section at any point
along its length (see Fig. 3). For proper heater support, the
maximum distance between clamps must not exceed 48”. On
extra-long heaters, more than two clamps are furnished.
2. Mounting Holes — When heaters are mounted adjacent to
each other in the same plane, note that distance between
mounting holes on framing to support heaters will be 4
1 /
4
” min-
imum. When heaters are not in the same plane, i.e., set at an
angle to one another, distance between mounting holes in fram-
ing will be either greater or less than 4
1 /
4
”.
3. Framing — Where an extensive installation is being made, the
use of continuous slot metal framing manufactured by several
concerns will be of assistance in saving time and money. The
framing is reusable.
4. Reflector Spacer Sheets — Where heaters are not mounted side
by side (see Fig. 4), reflector spacer sheets can be used between
heaters. These reflector spacer sheets and companion reflectors
consisting of an extruded aluminum housing with reflector sheet
and mounting clamps are available. Check factory.
5. Insulation — Where unusually high work temperatures are
encountered, it may be desirable to insulate behind heaters with
high-temperature fibrous insulation. A suggested method of
accomplishing this is indicated in Fig. 4.
6. Ventilation — Where solvents, water, etc. are being evaporat-
ed from work in process, it is necessary to provide substantial
quantities of ventilation air to carry away the resulting vapors.
FIRE HAZARD. Since Radiant heaters are capable
of developing high temperatures, extreme care
should be taken to:
A. Keep combustible materials at least 6” away
form sides and back of heater housing and its
supporting brackets and spaced far enough in
front of heater (heating element side) so thermal
radiation from the elements will not ignite com-
bustible materials.
B. If combustible materials are being processed,
stoppage of process should initiate immediate
heater shutdown and interception of residual
heat from radiant heaters (use radiation baffles
or move heaters away from work).
C. In the case of solvents of an explosive nature,
ventilation air must be in sufficient volume to
dilute the solvent vapor so that explosive mix-
tures cannot occur, refer to NFPA 86, Standard
for Ovens and Furnaces.
WIRING
ELECTRIC SHOCK HAZARD. Disconnect all power
before installing or servicing heater. Failure to do
so could result in personal injury or property dam-
age. Heater must be installed or serviced by a
qualified person in accordance with the National
Electrical Code, NFPA 70.
ELECTRIC SHOCK HAZARD. Any installation
involving electric heaters must be performed by a
qualified person and must be effectively grounded
in accordance with the National Electrical Code to
eliminate shock hazard.
1. Electrical connection to the Radiant Heater is made through the
3 /
4
” diameter conduit opening in the terminal box.
2. Access to Radiant Heater terminals is obtained by removing
the terminal box cover.
3. Wiring should be run in flexible or rigid metal conduit and
must be installed in accordance with the requirements of the
National Electrical Code and such other local requirements as
may be applicable. Note: High temperatures will oxidize cop-
per. Do not use copper wire in connecting this heater. Stranded,
insulated, nickel-plated copper wire is recommended.
4. Wires supplying power to heating element terminals shall have
insulation rated for 150°C minimum.
High Temperatures will oxidize copper. Use only nickel-
plated copper wire for supplying power to heater. Do not
use aluminum conductors.
5. A sufficient length of this wire (not less than 12”) should be
used to extend from each heater terminal into a connection box
location where the temperature does not exceed 300°F.
6. Assemble terminal, screw and wire as shown in Fig. 5.
7. Hold terminal with pliers and tighten the terminal screw
securely with a screwdriver.
Note: Where circuit wiring is installed in locations of high
ambient temperature, conductors should be insulated in accor-
dance with requirements for temperature and voltage.
Mounting Frame
Reflector
Spacer Sheet
Insulation
Figure 4
Figure 5
1 / " 8
7
2 / " 3 8
3 / " 11 16
INSTALLATION
Figure 2 Figure 3