Watlow WATROD Flange Heater - Manual (Page 3)

WATLOW IND.
WATROD Flange Heater Installation & Maintenance Manual
I&M NUMBER: 316-42-8-1 Page: 3
Date:6/11/2008 Rev: 2.00
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WATLOW IND.n # 6 INDUSTRIAL LOOP RD. n HANNIBAL MO, 63401n PHONE 573-221-2816 n FAX 573-221-3723
The location of an immersion heater in a process is of prime importance. To take advantage of natural
convection, the unit should be located as low as possible; similar to the position in Figure 1.
Consideration should also be given to sludge build-up in the bottom of the tank and the need for heater
removal (replacement or maintenance). Location of the heater in the sludge area will cause premature
failure and lower heat transfer efficiency.
If heater is being installed in customer supplied circulation tank, a Tubular Circulation I&M manual should
be obtained from the factory to ensure safe installation of heater in tank. Failure to do this could result in
premature heater failure due to improper fluid flow over elements
SLUDGE
LIQUID LEVEL
2" MIN
ANSI WELD NECK FLANGE
TO MATCH HEATER FLANGE SIZE
HEATER REMOVAL
ALLOWANCE FOR
Figure # 1
DANGER: HAZARD OF FIRE. Electric heaters are capable of developing high temperatures so extreme
care should be taken to locate heaters in safe environments. Mounting heaters in atmospheres
containing combustible gases and vapors should be avoided. According to article 501 of the NEC, the
maximum surface temperature of the heater shall not exceed 80 % of the auto-ignition of the surrounding
atmosphere when the heater is continuously energized. Care should also be taken to keep combustible
materials far enough away to be free of the effects of high temperatures.
5. Wiring
WARNING; HAZARD OF ELECTRIC SHOCK. Any installation involving electric heaters must be
grounded to earth to eliminate shock hazard.
Electrical wiring to the heaters must be installed in accordance with the National Electric Code and any
state and local electrical code by qualified personnel.
Consult wiring diagram supplied with the unit for correct feeder wires connections. If one is not supplied,
the factory should be consulted for the appropriate wiring diagram. Feeder wire should be properly
selected based on amperage, electrical power rating, ambient temperature, and type of environment.
Feeder wire should also be housed in either rigid or flexible conduit which carries the same classification
as the heater enclosure. It is the users responsibility to properly size and install feeder wire.
Feeder wire line connections may be made directly to stud terminals or box type compression fittings.
Box type compression fittings will accept a #4 AWG maximum wire while stud terminals will accept a
#10 ring connector(T&B, Amp, etc.). It is essential that these connections be tight. Stud terminals should
be tightened to a maximum torque of 20 in-lbs while the bottom nut is supported. Ground connection
(color coded "green") is supplied inside the housing for ground wire.