Watlow WATROD Duct Heater - Manual (Page 6)

WATLOW IND.
WATROD Duct Heater Installation & Maintenance Manual
I&M NUMBER: 316-42-6-1 Page: 6
Date:6/11/2008 Rev: 3.00
________________________________________________________________________________________________________________________________________________________________________________________________________________________
WATLOW IND.n # 6 INDUSTRIAL LOOP RD. n HANNIBAL MO, 63401n PHONE 573-221-2816 n FAX 573-221-3723
Heaters may be ganged in parallel for nearly any total wattage desired. The temperature control
thermocouple if so equipped should be located near the outlet to sense exiting air temperature. It may
be desirable to use in inlet and outlet temperature sensor for cascade style control. Conduct process
temperature sensing in the outlet stream away from the heater.
Minimum air velocity through the heater is 200 fpm for air temperatures approaching 800
°F (412°C).
Lower velocities will jeopardize element life.
Air flow over the entire face of the heater should be uniform throughout the cross section of the ductwork
before entering the heater bundle at the design velocity.
The units screw or bolt in place through the 3/8" (9.525 mm) dia. holes in the mounting flange. When
installed vertically through the top of the duct, they are self supporting when the duct is capable of
supporting the heater weight.