Chromalox PF451-3 - Manual (Page 2)

IMPORTANT
Failure to understand and follow these installation instructions
and the “WARNING” notes therein may result in serious per-
sonal injury from electrical shock, or from the heater falling due
to faulty installation.
WARNING: This heater is not recommended for
use in hazardous atmospheres where flammable
vapors, gases, liquids or other combustible atmos-
pheres are present as defined in the National
Electrical Code. Failure to comply can result in
explosion or fire. For these applications see
Bulletin PDS CXH-EP (PF305).
WARNING: Hazard of Shock. Disconnect all power
before installing heater.
The heater must be mounted at least 7’ above the floor to prevent
accidental contact with the heating elements or fan blade which
could cause injury.
The ceiling structure, the brackets, hangers or chains used to sus-
pend the heater, and the anchoring provisions must be of sufficient
strength to support the combined weight of the heater installation
(85 pounds for VUH-C-15, 20, 25 plus the weight of the supports).
Prior to operating the heater verify that the fan hub setscrews are
tightened and the push-on clip is secured to assure that the fan
blade is securely fastened to the motor shaft.
On models connected to three-phase power, fan blade rotation
must be checked. If airflow is not downward, interchange any two
of the three customer power leads.
First stage of thermostat must be connected to terminals C1 and
C2 to insure proper operation of overheat protective devices.
INSTALLATION
WARNING: Hazard of Shock. Any installation
involving electric heaters must be effectively
g r o u n d e d i n a c c o r d a n c e w i t h t h e N a t i o n a l
Electrical Code.
1. Heater should be positioned with the junction box facing away
from walls to provide easy access for servicing relay(s)
mounted within.
WARNING: Mount the heater for down discharge
only.
2. It is important that the 12” minimum dimension shown in
Figure 1 be maintained to make it possible for a serviceman to
remove the fan motor, if necessary, without moving the heater
from its mounting.
WARNING: The heater must be mounted at least
7’ above the floor to prevent accidental contact
with the heating elements or fan blade which
could cause injury.
The ceiling structure, the brackets, hangers or chains used to sus-
pend the heater and the anchoring provisions must be of sufficient
strength to support the total weight of the heater installation (85
pounds for VUH-C-15, 20, 25 plus the weight of the supports).
3. The heater may be mounted to the ceiling by attaching rigid
angle brackets, hangers, or chains to the four mounting holes
on the top of the heater case using four 5/8” bolts (by others).
See Figures 1 and 2.
Note: Brackets, hangers, or chains to support the heater are
supplied by the customer.
4. All wiring should be done in accordance with local codes and
the National Electrical Code by a qualified person as defined
in the NEC.
WARNING: Use Copper conductors only.
5. Rough-in wiring to heater. See Table 2 for line amperes, rec-
ommended wire size and conduit size.
6. Wire heater per wiring diagram supplied with this instruction
sheet.
Note: Power relay(s) are provided as standard on all heaters.
WARNING: Prior to operating the heater, verify
that the fan hub setscrews are tightened and the
push-on clip is secured to assure that the fan
blade is securely fastened to the motor shaft.
7. Carefully inspect the completed installation. Rotate the fan
blade by hand to be sure that it turns freely. Investigate any
binding, rubbing or interference.
8. Air diffusers for deflecting the air are optional. See Instruction
Sheet PF449 for Installation instructions.
Power Supply Circuit Contactor
Holding Coil Motor
Model
Line Line
Minimum
Volt Ampheres
kW Volts Phase Amps Wire Size
No. Conduit
(Note 3)
(Note 1) (Note 2)
Circuits Size †
(In.) Inrush Sealed
Volts H.P. Phase
208 3 43 6 1 1 208
VUH-C-15 15 240 3 37 8 1 1 52 9 240 1/6 3
480 3 19 10 1 1/2 480
VUH-C-20
19.5 240 3 48 6 1 1 240
20 480 3 25 8 1 3/4
52 9
480
1/6 3
VUH-C-25 25 480 3 31 8 1 3/4 52 9 480 1/6 3
Table 2 - Electrical Data
Notes:
1. Includes Fan Motor Amps.
2. Use 75˚C Wire - Copper Conductors only.
3. Standard units have one contactor. Units with separate fan motor control use two contactors.
† Conduit knockout location - top of Junction Box.