Reznor, AB - 2 Gas, GB 2019-08, D301177 Issue A PAGE 9
A customer specific control panel wiring
diagram will be supplied with each air
curtain
Burner controls
The burner controls are mounted in the burner
control cubicle which is an integral part of the air
curtain casing and are accessible by opening a
hinged lid on the right hand side of the air curtain
(see page 15 of this manual for details). The
controls accessible in the cubicle are: gas solenoid
valve, ignition controller, air pressure switch,
flame probe, ignition electrode, reset switch,
orange and white lamps, plus associated wiring
harness. For details see burner wiring diagram on
page 8.
Control panel
The electrical control panel incorporates the
facility to interlock with the door opening
mechanism and automatically switch the air
curtain between high/low speed as the door is
opened and closed. A pair of volt free auxiliary
contacts are required on the door open/close
contactor which closes as the door opens. If this
is not available then a suitably positioned limit
switch and striker plate will need to be fitted to
the door.
The panel incorporates an auto/off/manual
selector switch, which, when in ‘auto’ mode
operates the air curtain in low speed via an
external room thermostat provided the door is
the down position. In the door up position the air
curtain operates in high speed and overrides the
room thermostat The ‘manual’ position overrides
the door interlock and thermostat, and the ‘off ‘
position turns the air curtain off.
A cool/heat selector switch is also incorporated
which allows the air curtain to supply heated air,
or unheated ambient air.
The panel also contains a removable link on the
main terminal rail to allow the air curtain to be
switched on and off remotely via a BMS control
relay.
The panel may also be fitted with optional low
voltage (24V AC) relays for fire alarm/door
contact interlocks.
Regardless of the position of any of the above
switches, the main air fans must be running to
allow the burner to run.
Overheat protection
In the event of any overheat condition there are
two thermal limit controls fitted inside the air
curtain. The controls are factory set and non-
adjustable. The self resetting (cycling) control
activates at 63ºC (AB 225N) and 51.5°C (AB
175N), and the manual reset control at 96ºC. If
either set point is reached, the corresponding
limit control will interrupt the electrical power to
the burner gas valve. The burner will not relight
until the limit control has reset. The manual reset
button is located on top of the heater on the left
hand side of the thermostat cover and can be
accessed after first removing the dust cover. (See
Figs. 22).
These safety devices provide protection in the
event of an air distribution fan motor failure, or
lack of airflow due to restrictions. (For location
see ‘Parts Replacement’ section Figure 40,
and ‘Wiring Details’ section on page 8, burner
controls wiring diagram).
Warning: never attempt to bypass
the thermal limit controls as
hazardous conditions could result.
Wiring Details (Cont)...
Figure 11.
