Qmark High Velocity Electric Heated - Manual (Page 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 contaminant’s.
Maintains interior conditioned temperature by preventing heated or
cooled air from escaping through open doorways. Heated air cur-
tains 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 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 36
inches.
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 keep on going.
Each cabinet in a multiple cabinet installation are independent of
each other as far as the operation of the auto resets are con-
cerned. 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 defective or the automatic reset protective
devices 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
wheels loose or turning in the wrong direction.
These air curtains are provided with a pressure differential switch
with the sensing tube located on the low pressure or suction side of
the switch and the other end on the inlet side of the blower. It has
been so located that when the motors are rotating in the wrong
direction there will not be enough suction to close the normally open
contact of the pressure switch and thus prevent the heating contac-
tor and the associated pilot light from coming on. When this hap-
pens check for correct rotation of the motor and for anything else
that may cause the blower from delivering the required air flow.
UNPACKING
For Single Cabinet Units: 42”, 48” and 60”
1. With packaged unit on the floor, carton arrows should point
upward.
2. Carefully remove staples from top of carton and fold back sides.
3. Carefully remove cabinet from carton by lifting out unit using fin-
ger holes in styrofoam side inset and place on work surface.
CAUTION: Do not attempt to lift this air curtain by its louver or
damage may result.
4. Unscrew six (6) knurled nuts and remove air intake grille. (See
Figure 3)
5. Carefully disconnect motor electric cord from socket and plug
assembly and remove two wing nuts on blower base. (See
Figure 4)
NOTE: Unit is shipped with styrofoam motor support block which
must be discarded at this time.
6. Carefully remove pressure switch hose from clamp on the right
blower.
!
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.
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
!
Figure 3