Watlow FIREBAR Circulation Heater - Manual (Page 2)

WATLOW IND.
FIREBAR® Circulation Heater Installation & Maintenance Manual
I&M Number: 316-42-1-1 Page: 2
Date: 06-11-08 Rev: 2.00
________________________________________________________________________________________________________________________________________________________________________________________________________________________
WATLOW IND.n # 6 INDUSTRIAL LOOP RD. n HANNIBAL MO, 63401n PHONE 573-221-2816 n FAX 573-221-3723
Failure of components in a temperature control loop, such as the sensor, heater control relay or main
temperature control, can result in damage to a product in process, a melt down of a heater, and / or
damaging fire.
To protect against this possibility, over temperature protection must be provided to interrupt or remove
power from the heater circuit. A bulb and capillary thermostat is not recommended for this function
since it may not respond quickly enough to adequately protect the heater. In cases where the
thermostat bulb gets too hot before the system is turned off, the thermostat bulb could rupture.
This could result in the thermostat remaining in the "ON" condition since there is insufficient
fluid to move contacts apart. We recommend the temperature protection have appropriate third party
approval, and be applied in the classification for which it was tested and approved.
In order to help prevent premature failure and a potentially hazardous condition in cases where
consequences of failure may be severe, use an appropriate third party approved liquid level protection
device. The liquid level should be such that the entire heater is fully submerged with enough liquid above
the heater to adequately dissipate heat from itself as under normal operating conditions. Consult your
local authorized sales representative for specific recommendations for your application.
3. Terminal
Enclosures
Terminal enclosures should be selected to be compatible with the environment in which the heater will
be located. It is the users responsibility to determine the need for correct rating of the electrical housing.
This should be based on appropriate national and local electrical codes. Failure to use a compatible
enclosure could result in heater damage and personnel danger.
Standard terminal enclosures are designed for general purpose use and are rated NEMA 1. These
enclosures should be applied where there will be no danger of spilled liquids, dampness, dirt, and
gaseous conditions. Enclosures for wet or hazardous locations are also available, but must be installed
at the factory.
Although enclosures are supplied over the terminals, units should be located in an area that will minimize
the chance of being hit by falling or moving objects. The terminals must be protected at all times from
moisture or vapor.
In hazardous locations, (as defined in NFPA 70, NEC, Article 501) explosion resistant housings must be
used.
In order to maintain termination integrity, the terminal enclosure should be kept below 400
°F
(204
°C).
4. Orientation / Mounting
Proper installation and orientation of the FIREBAR® Circulation Heater is important to insure maximum
efficiency and minimum sheath temperatures. The unique shape of this flat element offers many
advantages, but they can only be realized if the heater is properly oriented. Every effort should be made
to position the heater as recommended.
When the FIREBAR® immersion heater is located in a tank the preferred tank orientation is shown in
Figure # 1. The tank should be mounted horizontally with both nozzles out the top. In this position the
"TOP" marking on the heater flange or screw plug should be positioned on top. This ensures that natural
convection can occur within the tank, even though the primary flow may be created by a pump. Also,
heaters with element supports require special attention to insure that they are not positioned to restrict
flow. The element supports create a baffling effect and must be installed so that the nozzles and "TOP"
are both ositioned up.