-4-
VII. MAINTENANCE AND CLEANING
CAUTION: ELECTRIC SHOCK HAZARD:
Disconnect power when servicing unit.
More than one disconnect may be required to de-energize
unit.
Keep your air door operating at peak efficiency by cleaning
the blower wheels, motor(s) and intake grille. Build up of
dust on the blower wheels can cause vibration, noise and
excessive wear on the motor bearings. The frequency of
cleaning will depend on the environment where the unit is
operating.
Dirty, dusty or greasy environments could require a cleaning
schedule of once every two months. If the environment is not
that dirty, the unit(s) should be scheduled for cleaning a
minimum of once every (6) months.
To remove the filter:
This unit is equipped with a “No Tool” filter removal. Simply,
pull the (2) black tabs, located underneath the intake grille,
outward. This action releases the filter which then can be pulled
downward out of the unit (See Figure 4).
FIGURE 4 -Filter Removal
To clean the interior of the unit:
A. Disconnect the power to the unit; remove the intake grille by
removing the (4) screws on one side of the unit. Pull the top
of the end cap outward to release the filter tab to remove
end cap. Slide the intake grille out of unit (See Figure 5).
It is not recommended to remove the blower assembly from
the cabinet. To clean the motor and blower wheels, with the
filter and inlet screen removed, blow compressed air in the
unit to remove loose dust and debris.
CAUTION: STAND CLEAR OF THE UNIT OR WEAR SAFETY
GOGGLES AS LOOSE DEBRIS MAY BE PRESENT AND MAY
EXIT THE NOZZLE.
B. Connect power and switch the power on after cleaning.
IV. ELECTRICAL CONNECTIONS
All electrical wiring and connections MUST be performed
by qualified personnel in accordance with the National
Electrical Code ANSI/NFPA No. 70 (latest edition) or, in
Canada, the Canadian Electrical Code, Part 1-C.S.A. Standard
C22.1, and local codes and regulations.
A. Check the rating nameplate on the top of the unit for supply
voltage and current requirements (See Figure 2). Unheated
units may be plugged into any 15 or 20 amp receptacle.
Heated units require a dedicated 20 amp receptacle
and circuit. A disconnect switch for each branch circuit is a
required part of this installation (See Table 2).
B. All field wiring must be copper with a minimum insulation
of 60°C within approved conduit. If any of the wire supplied
with the unit must be replaced, it must be replaced with
copper wiring with a minimum insulation of 90°C.
V. OPERATION AND CONTROLS
A. The unheated Drive-Thru Unit air door operates with a two
position on-off switch.
B. The heated Drive-Thru Unit air door operates with a three
position fan-off-heat switch.
VI. AIR FLOW ADJUSTMENTS
A. With the air door operating and the door in its full open
position, check to see that nothing is obstructing the air flow
at the discharge nozzle vanes.
B. Find the air stream split location. Hold a handkerchief or
tissue, by its corners, approximately 4” above the counter.
Gently move the handkerchief back and forth in the
doorway. Make sure the air is being directed to both the
inside and the outside. The split location is indicated where
the handkerchief is vertical with minimal or no fluttering.
C. Rotate the air curtain by adjusting its position in the
mounting bracket so the split location is approximately 2”
outside the window (See Drawing 1).
Motor Voltages/Amp Draws
DTU1018AA DTU1018EA DTU2026AA DTU2026EA
Volts
120
120
120
120
Phase
1
1
1
1
Hertz
60
60
60
60
Amps per unit
1.6
18.3
2.2
18.9
kW
0
2
0
2
TABLE 2
