Indeeco 781 SERIES Installation, Operating, & Maintenance Instructions page 2

Mechanical Instructions
Site Selection
Review the NEMA Type rating of the heater noted on the
INDEECO Application Data. Do not install a heater in an
area not consistent with its rating. The standard configuration
provided is NEMA Type 4, intended for outdoor use.
Allow sufficient free space around heater installation site.
Work space for heater maintenance should be at least three
feet in front and on either side of the heater. The minimum
pull space for the heating element installation or removal from
the pipe/tube should be at least four feet. The heating
element is designed to be flexible and can be curved if
necessary.
Leave a minimum of 6" clearance to any SCR heat sinks
mounted through the side of panels to allow proper cooling.
Electric heaters are capable of developing high temperatures.
Therefore, extreme care should be taken to
avoid mounting heaters in an atmosphere containing
combustible gases, vapors, dusts, or fibers unless properly
marked as suitable for the condition.
Heater Orientation
This style of heater is intended for horizontal use only. The
open coil resistance wire must not be mounted in a vertical
orientation or failure could occur from the coil sagging.
The heater must be mounted plumb horizontally to assure
proper operation.
Thermal expansion of the heater pipes must be considered
when locating the heater. It can be approximated as:
Pipe
Length x .00001 x
(Inches)
If the heater is installed in a pressurized tank, a relief valve
must be installed. As a minimum, the valve must be sized to
relieve at a rate equal to the rate that the heater can thermally
expand fluid in the tank.
Pipe Assembly Installation
On assemblies provided with ANSI flanged connections, take
care to prevent scratching the flange faces. INDEECO
supplies a non-asbestos nitrile bonded fiber flange gasket
unless otherwise requested. The user must confirm that the
gasket is suitable for the application. The user must supply
high strength studs or bolts and nuts, such as A-193 GR. B7
and A194 GR. 2H, rated for the design conditions. Bolts must
be properly installed and tightened to prevent leaks.
When an adapter box is provided, the assembly is welded
directly to the user's tank wall. A rectangular cutout is
required; not to exceed the adapter box dimensions plus ¼".
Max Pipe
Operating
- 70°F
Temp (°F)
Heater pipes must be supported inside the user's tank.
Supports must not prevent the pipes from thermally
expanding. Supports should be located on a maximum
spacing of 10 feet.
Where buildup of solids in the bottom of the tank is expected,
the pipes must be located above that level. The pipes must
also be located below the minimum operating fluid level of the
tank.
Heater pipes must be perfectly clean before installation of
heating element. Use only a clean dry cloth to clean. Never
use a lubricant. Compressed air with a long wand may be
used to remove ceramic chips, etc.
Insulation
Surfaces of the heater pipes extending beyond the
user's vessel may be extremely hot. Avoid contact to
prevent personnel injury or fire.
The customer may prefer to insulate the flange or adapter
box at the tank for personnel safety and energy conservation.
Do not insulate the terminal enclosure or the first 2" of
the pipe. Dangerous over-heating of the terminal box
wiring could result.
The heating elements are provided with a "cold section"
where stainless steel bussing is used to connect to the
heating coils. This area must be packed with insulation to
prevent over-temperature of the terminal enclosure.
Insulation was factory installed before shipment.
Electrical Instructions
The potentially high operating and ambient temperatures of
Storage Tank Heaters require field wiring to the heater be
carefully matched to the application, to avoid serious injury or
damage to the equipment. The wiring must be de-rated for
the expected terminal box temperature. Terminal box
temperatures are typically below 120
can be expected for heaters used in cold climates for freeze
protection. If the cold section of the heater is properly
o
insulated, 90 C minimum wire may typically be used. Refer
to the National Electrical Code.
The size and type of incoming field wiring will depend upon
the heater terminal box temperature, heater current draw per
conductor, number of conductors per conduit, and wire
insulation rating. Field supplied conductors must be sized for
at least 125% of the circuit current.
To calculate the circuit current (in amps):
Single phase
Line current
2
WARNING
WARNING
o
F. Lower temperatures
KW x 1000
Line Voltage