Chromalox PG417-3 - Manual (Page 2)

INSTALLATION
4. Refer to Figure 2. Assemble one flat lock nut onto one end of
each support tube or conduit and thread them into the tapped
openings in top of heater. One of these support tubes contains
three insulated wire leads. Handle with care to avoid damage
to lead insulation.
WARNING: Do not cut the support tube for in doing so the
minimum 12” clearance to ceiling will be violated resulting in
excessive ceiling temperatures. Tighten lock nut securely
against heater case.
5. Slip the canopies loosely over the fixture support tubes.
6. Assemble remaining locknuts onto ends of support conduits. Flat
nut goes on first; spherical nut last with its convex side facing
heater. See Figure 2. There should be full thread engagement at
the top spherical nut. Allow about
1 /
2
” spacing between nuts to
facilitate hanging to brackets. Set the assembly aside.
7. WARNING: Hazard of Electric Shock. Disconnect
all power to ceiling wiring box to which one
heater support will be fastened.
8. Install special cover plate and saddle bracket, provided with
heater, over ceiling wiring box after fishing insulated power
leads and ground lead, if provided, through large opening in
cover plate. Use mounting screws provided with wiring box.
9. Mount remaining saddle bracket to ceiling at the remaining
planned point of support. The brackets should be on B dimen-
sion centers given in Specifications — Table A.
10. Raise heater assembly, and slide both spherical nuts through
slot in saddle brackets until spherical nut rests in the slot
depressions. Run bottom lock nut up against bracket to lock
the assembly into place.
WIRING
OPERATION
WARNING: Hazard of Electric Shock. Any installa-
tion involving electric heaters must be grounded to
earth to eliminate shock hazard.
1. All wiring to heater wiring box shall be in accordance with
National Electrical Code and/or local wiring code.
2. Power conductors should be sized to handle 125% of heater
current given in Specifications — Table A.
3. Complete electrical wiring between heater leads and power
leads using insulated wire nuts. Tuck excess lead around and
behind saddle brackets.
4. The green colored ground lead should be
connected to ground lead from wiring box,
or if such lead is not provided, then the
ground lead should be grounded to the con-
duit box to insure ground continuity. Note:
If heaters are to be suspended more than 12”
below ceiling, the heater support tubes
should terminate into a Crouse-Hinds Type
C Condulet in line wiring box where splice
to power leads can be made (See Figure 3).
A
3 /
8
” pipe or conduit extension of the
desired length from top of Condulet can
then terminate at the ceiling wiring box uti-
lizing cover plate, brackets, and lock nuts as
with conventional installation.
5. To complete installation raise canopies to completely enclose
brackets and electrical wiring. Tighten set screw.
6. If wiring from heater becomes damaged or requires replace-
ment, it should be replaced with special high temperature wire
as furnished with heater. Replacement wires can be ordered
from Chromalox. (See RENEWAL PARTS section.)
DANGER: Fire Hazard. This heater is not intended
for use in hazardous atmospheres where flamma-
ble vapors, gases, liquids or other combustible
atmospheres are present as defined in the National
Electrical Code. Failure to comply can result in
explosion or fire. 1. Although most heaters operate at full capacity, it is possible to
reduce heating capacity with an Input Controller (Chromalox
Type VC or VCR — check factory) which can be manually set to
turn on heaters from 4% to 100% of a 15 or 30 second operating
cycle, providing, in effect, infinite control of heater output. Refer
to Figures 4 and 5 as may be appropriate to your installation.
Maximum number of Heaters limited by 25 AMP. — 120 Volt, 20 AMP. —
240 Volt Controller Rating.
The VC or
VCR
15 or 30
Second
Input
Controller
120 or
240V
SKR
Heaters
Wired 1ø
Contactor
SKR Heaters
Wired 1ø or 3ø
120, 208, 240, 275,
480 Volt Single
or Three Phase
Limiting Thermostat (Optional)
Input
Control
120 or
240V
Single Phase Wiring — Solid Line
Three Phase Wiring — Dotted Added
(Type VC or VCR) when voltage and load current exceed controller capacity
{
{
SKR Radiant Heater Control by Input Controller
Figure 4
Figure 5
Figure 3
Cover Plate
Spherical Locknut
Saddle Bracket
Flat Locknut
Canopy
Flat Locknut
3-1/1/4or 4" octagonal
box to be installed in
ceiling at one end of
heater location. (Cus-
tomer furnished).
3/8” Stem
Figure 2