Qmark Environmental Electric Heated - Manual (Page 3)

3
GENERAL INFORMATION
Air curtains produce a wall of continuously flowing air that acts as
a thermal barrier against outside air and provides protection
against insects, dust, odor, fumes and other contaminants. Air cur-
tains maintain interior conditioned temperature by preventing heat-
ed or cooled air from escaping through open doorways. Heated air
curtains are engineered to treat incoming cold air at customers’
entrance areas. Used over front door entrances, heated air cur-
tains supplement existing heat to prevent infiltration of colder out-
side air. Heated units are not recommended for areas subject to
high winds.
The heated air curtains covered by this Installation & Maintenance
Instructions are permanently installed units intended for permanent
connection to a single electrical supply source and are intended to
be located over doorways at least 7 ft. above the floor. The units
may be installed with zero minimum clearances from combustibles
on three sides of the unit and the minimum clearance from the
adjacent wall to the hinged door of the main control box is 16 inch-
es.
Each cabinet employs a dual shaft motor, driving two blower type
air circulators causing air flow over a heater assembly. The heater
assembly consists of two sections, one section per blower. The
heater assembly is controlled by contactors with 24 volt AC low
voltage coils. A replaceable thermal cut-off or one shot protective
device is provided on each leg of each assembly. Each section is
provided with an automatic reset overheat protective device. In
case of overheating, the automatic resets will shut off only the heat
contactor for the heater assembly in the cabinet associated with it
and not the fan contactor and thus airflow should continue. Each
cabinet in a multiple cabinet installation are independent of each
other as far as the operation of the auto resets are concerned.
Each cabinet will have its own control compartment with a heating
contactor with an indicator light and a fan contactor and the
required control terminals for interconnection.
When facing the inlet grille of the unit, the main control box is
attached on the right side of the combination. A maximum of three
supplementary 60 amp rated circuit breakers (or 60A load fuses)
will be provided for units with full load rating greater than 48 amps.
Field control terminal blocks are also provided with the Main
Control box. A class 2 certified, 24V secondary, 75 VA control
transformer is provided. Class 2 wiring may be used for controls
but it is recommended to use Class 1 wiring for controls since
these are usually located in a commercial-industrial environment.
The load on the thermostat will always be one small relay (4VA) for
heat and another relay for the fan circuit whether the unit is a sin-
gle, a double or a triple cabinet installation. Any standard low volt-
age (24V) heating thermostat may be used.
On the Main Control Panel are three indicator lights. These lights
serve the following functions:
Top Light - Power is on to the unit.
Middle Light - The heating elements are on in the unit.
Bottom Light - The fan is on in the unit.
If the “HEAT ON” light is lit at the Main Control Box, the indicator
light at each cabinet control compartment should also be lit. The
cabinet with an unlit light in this instance will need investigation.
Either the bulb is burned out or the automatic reset protective
device in this cabinet has functioned and taken the heating con-
tactor out of circuit. The airflow should also be checked on this
cabinet. The air passageways may be blocked or the blower
wheel is loose or turning in the wrong direction.
Initial Start Up - Checking For Correct Fan Motor Rotation:
On all three phase units, it is essential for the units to be checked
for correct fan rotatino since it is always possible the motor could
be rotating backwards. Before energizing the units, make sure
units are fully assembled, all wiring is correct and cabinet doors
are closed. Energize units and observe air flow from exhaust. If
correct, the discharge airflow will be strond and the heater ele-
ments will come on in a short time to provide heaterd air. All three
indicator lights will be on when the heater and fan are on.
If motor rotation is backwards, interchange any two wires to the
motor and check to see that the motor rotation is correct.
When Removing Blower Assembly From Cabinet(s):
If it becomes necessary to remove the blower assembly from the
cabinets, care must be given to assure the sensing tube for the
pressure differential switch is reassembled correctly and in the
poper locations.
The sensing tube is provided with an in-line quick connector
located near the blower assembly so the tube can be easily dis-
connected and reconnected. This is the only portion of the tube
that should be disturbed during this process. To separate, hold
the body of the connector and push the release ring towards the
center of the connector body and then pull the tube from the con-
nector. To reconnect, push the tube into the connector unitil it is
secured in place.
!
WARNING
ALWAYS DISCONNECT POWER AT THE MAIN DISCONNECT
OR CIRCUIT BREAKER BEFORE INSTALLING OR SERVIC-
ING THIS HEATED AIR CURTAIN. IF THE POWER DISCON-
NECT IS OUT OF SIGHT OR IS LOCATED GREATER THAN
50 FEET FROM THE MAIN PANEL OF THIS HEATED AIR
CURTAIN, LOCK THE MAIN DISCONNECT IN THE OPEN
POSITION AND TAG IT TO PREVENT UNEXPECTED APPLI-
CATION OF POWER. FAILURE TO DO SO COULD RESULT
IN FATAL ELECTRICAL SHOCK.
!
WARNING
DURING INITIAL POWER UP OF HEATED AIR CURTAINS,
HINGED CONTROL DOOR MUST BE IN CLOSED POSITION
FOR CORRECT OPERATINO OF THE PRESSURE
DIFFERENTIAL SWITCH. ENERGIZING UNIT WITH DOOR
OPEN MAY CAUSE PERMANENT DAMAGE TO HEATING
ELEMENTS. SEE DETAILS BELOW.
THIS HEATED AIR CURTAIN AND ITS SUB-ASSEMBLIES AND
CONTROLS SHOULD BE INSTALLED BY QUALIFIED PER-
SONNEL, USING COPPER WIRES AND IN ACCORDANCE
WITH THE NATIONAL ELECTRICAL CODE (NEC) AND ALL
APPLICABLE LOCAL CODES AND ORDINANCES.
NOTE: A MAIN DISCONNECT OR CIRCUIT BREAKER IS
REQUIRED AHEAD OF THE MAIN PANEL OF THIS HEATED
AIR CURTAIN.
!
WARNING
TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK, DO
NOT USE THIS AIR CURTAIN WITH ANY SOLID STATE
SPEED CONTROL DEVICE.
CAUTION
!
CAUTION
!
INCORRECT INSTALLATION OF THESE TUBES WILL RESULT
IN THE UNITS NOT OPERATING PROPERLY AND COULD
CAUSE PERMANENT DAMAGE TO UNITS