CCI Thermal Technologies RXDF - Explosion-Proof Duct Heater - Manual (Page 3)

CCI Thermal Technologies Inc. 2767 Brighton Road, Oakville, ON L6H 6J4 Tel. (905) 829-4422 Fax (905) 829-4430
www.ccithermal.com
MI289 REV.1 Page 3 of 4
6.0 WIRING
Whenever hazardous materials are present,
ensure that the terminal housing covers,
plugs, etc., are secured (but not over-
tightened) before energizing the heater.
All circuits must be in the open position before
removing junction or terminal box covers.
Use supply wires suitable for 90°C. Supply
wires are to be fused with appropriately sized
HRC fusing.
Use approved conduit and conduit seals as
required by hazardous location standards.
Ensure that no power is connected to the
equipment prior to making any connections.
6.1 The heater is factory prewired to supply terminal blocks in
the heater terminal housing ready for direct connection to the power
supply. The heater also contains one (1) high limit thermocouple
per heating bank that must be wired to the control equipment.
For double bank heaters, Heater Bank #1 is
defined as the inlet bank and Heater Bank #2
is defined as the outlet bank. This distinction
is important in order to ensure proper high
limit set limit set points must be set in the
field. Table 2 gives the maximum high limit
set points for safe operation of the heater. For
initial start-up, set the high limit controllers
to the values indicated in Table 2.
6.2 To wire the heater to the control equipment, make the
following connections at the connection points indicated on the
assembly drawing:
a) 1¼" NPT conduit entries have been provided in each heater
terminal housing for wiring the power supply and ground to
the heaters. Connect the heating bank(s) to the contactor(s)
in the control panel.
b) ¾" NPT conduit entries have been provided on each heater
bank for wiring the J type high limit thermocouple(s) to
Certified, manual-reset high limit controller(s) in the control
panel. Using appropriate thermocouple extension wire,
connect the thermocouple(s) to the high limit controllers,
ensuring proper connection of the positive and negative
leads.
c) Connect the "Normally Open" contacts of the supplied
pressure differential switch to the interlocks in the control
circuit.
After all connections have been made and
before starting up the system, ensure that all
housings, plugs, covers, etc. have been
installed.
7.0 STARTUP AND OPERATION
TO ENSURE SAFE AND RELIABLE
OPERATION, DO NOT EXCEED THE MAXIMUM
OUTLET TEMPERATURE OF 40°C AND DO
NOT ALLOW THE AIRFLOW TO DROP BELOW
THE MINIMUM AIRFLOW AS SHOWN ON THE
PRODUCT NAMEPLATE.
7.1 Turn on the airflow through the duct heater. Ensure that
the minimum airflow, as shown on the product nameplate, is
maintained at all times.
7.2 The field installed explosion-proof differential pressure
switch may require field adjustment. Consult manufacturer's
operation instructions included with this manual.
THE PRESSURE DIFFERENTIAL SWITCH IS A
CRITICAL SAFETY COMPONENT. IMPROPER
SETTING OF THE SWITCH MAY RESULT IN
HAZARDOUS CONDITIONS.
7.3 Apply power to the control panel.
7.4 Turn the control on/off switch to "On".
7.5 Set the temperature controller to the desired set point. Do
not exceed the maximum outlet temperature of 40°C.
7.6 Ensure that the temperature controller is working properly.
Consult the manufacturer's operation instructions supplied with the
temperature controller.
7.7 Except when purchasing a control panel to accompany your
XDF heater, the high limit set points must be set in the field. Table
2 gives the maximum high limit set points for safe operation of the
heater. For initial start-up, set the high limit controllers to the values
indicated in Table 2.
TO PREVENT UNSAFE OPERATION OF THE
HEATER, DO NOT EXCEED THE MAXIMUM
HIGH-LIMIT SET POINTS. OPERATION OF
THE HEATER WITH HIGH LIMIT SET POINTS
GREATER THAN THOSE SHOWN IN TABLE 2
CREATES A SIGNIFICANT RISK OF
EXPLOSION.
Table 2 - Maximum High Limit Set Points
Tem perature Code T2D T3A T3B
Heater Bank #1 (Inlet) 94 78 65
Heater Bank #2 (Outlet) 125 100 83
High Lim it Set-Point (°C)