TM 11-6780-225-35
e. Circuit 5. Circuit 5, controlled by CB5 (40 amp),
2-5.
Heating and Air-Conditioning System
is an 8gauge wire supplying power to the ONOFF switch
of the water heater.
The function of the heating and air-conditioning system is
f. Circuit 6. Circuit 6, controlled by CB6 (20 amp) is
to provide heating, cooling or ventilation for the three
a 12gauge wire supplying power to eight CIRCUIT 6
compartments of the ES82A as follows:
outlets. The safelights are connected to these outlets.
hot air with hot air return (a below), air for ventilation (b
The refrigerator line plug is connected to the CIRCUIT 6
below), and cold air with return air (c below).
receptacle in the aft compartment.
a. Hot Air With Hot Air Return. With space heater
g. Circuit 7. Circuit 7, controlled by CB7 (20 amp),
UH684 in operation, the hot air is forced out through the
is a 12gauge wire supplying power to TB1 of the control
registers of the bottom roadside duct into the aft and
panel for the space heater, and film and print drying
center compartments, and out of the end of the bottom
cabinets.
roadside duct into the forward compartment.
The
h. Circuit 8. Circuit 8, controlled by CB8 (20 amp),
pressure of the hot air at the floor level of the ES82A
is a 12gauge wire supplying power to two CIRCUIT 8
being greater than at the ceiling level, forces the hot air
outlets. The repeating timers, enlargers, and print
into the registers of the top roadside and curbside ducts,
processors are connected to these outlets.
which now have become hot air return ducts.
i. Circuit 9. Circuit 9, controlled by CB9 (20 amp) is
When the top register of the bottom duct in the aft
a 12gauge wire supplying power to the control unit of the
compartment is in the open position, the hot air return is
processing unit.
drawn into the UH684 and recirculated. Fresh outside air
j. Circuit 10. Circuit 10, controlled by CB10 (30
is added to the recirculated hot air from the fresh air
amp), is a 12gauge wire supplying power to the water
intake. Each register may be closed to prevent hot
pump switch located in the forward compartment.
airflow, or adjusted to provide direction for the hot airflow.
k. Circuit 11. Circuit 11, controlled by CB11 (20
b. Air For Ventilation. Air for ventilation of the
amp), is a 12gauge wire supplying power to the
ES82A may be obtained by using either or both of the
incandescent light switches.
methods described below.
l. Circuit 12. Circuit 12, controlled by CB2 (20 amp),
(1) Unheated air from space heater. With space
is a spare circuit.
heater UH684 in operation to supply unheated air, fresh
2-3.
Enlarger and Repeating Timer
air is drawn in from the outside and forced through the
bottom roadside duct into all the compartments of the
ES82A.
Complete ventilation may be obtained by
a. Enlarger. Each enlarger has been modified by
operating the exhaust fans in the center and forward
removing the baseboard, shortening the girder assembly,
compartments. If weather conditions permit, the fresh air
and adding fixed stops to the girder assembly to prevent
intake door in the entrance door may be opened to
the lamp house from contacting the ceiling of the ES82A.
supply additional outside fresh air.
The girder assembly is secured to the wall at the bottom,
(2) Uncooled air from air conditioners. With
and by aluminum tubing at the top. Each enlarger is
each air-conditioner selector switch set to FAN as
connected to circuit 8 through a repeating timer.
required, and the fresh air controls set to OPEN, fresh air
b. Repeating Timer. The repeating timer controls
is drawn in from the outside and distributed through the
the enlarger lamp for focusing and for a predetermined
top roadside and curbside ducts into all compartments of
time for printing. The safelight may be connected to the
the ES82A.
If the space heater is operated in
repeating timer so that it will be extinguished during
conjunction with the air conditioners as described in (1)
focusing and printing.
above, the return air is drawn into the bottom curbside
2-4.
Equipments Covered in Other Tactical
duct and vented to the outside through the air
Manuals
conditioner's return air grills.
c. Cold Air With Return Air. The controls for air
The function of equipments not covered in chapter 2 will
conditioner No. 1 are self-contained. Air Conditioner No.
be found in the applicable technical manual listed in
2 has been modified by placing the thermostat control in
the aft compartment (air conditioner No. 2 thermostat),
providing
complete
2-3
