Direct Gas Make-Up Air
62
13
22
26
28
27
20
15
21
4
1
7 8
2
9
3
5 16 23
17
18
19
14
25
10
12
11
24
6
1.
Supply Motor Starter
— 24 volt magnetic contacts
for starting supply motor.
2.
Supply Overload
— provides electronic overload
protection to supply motor.
3.
Low Voltage Transformer
— provides low voltage
to fan/heat/cooling enable controls.
4.
Control Terminal Block
— provides wiring access
to controls.
5.
Fan Relay
— allows power to pass to energize
motor starter.
6.
Exhaust Auxiliary Contact (optional)
— provides
one normally closed and one normally open
contact for other equipment.
7.
Supply Auxiliary Contact (optional)
— provides
one normally closed and one normally open
contact for other equipment.
8.
Exhaust Motor Starter (optional)
— 24 volt
magnetic contacts for starting exhaust motor.
9.
Exhaust Overload (optional)
— provides
electronic overload protection to exhaust motor.
10.
Transformer Fuse (optional)
— provides proper
fusing for cooling transformer.
11.
Terminal Block
— provides wiring access to high
voltage circuits.
12.
Exhaust Fuses (optional)
— provides proper
fusing for exhaust fan motor(s).
13.
Dirty Filter Switch (optional)
— monitors filter
pressure drop, turns on indicating light when
pressure drop is above field-adjustable set point.
14.
Inlet Air Sensor (optional)
— outdoor air stat that
automatically controls the heating and/or cooling
based on outdoor air temperature.
15.
Remote Temperature Selector (optional)
—
allows for remote temperature set point.
16.
Heat Relay
— allows power to pass to heating
controls.
17.
Heating Terminal Block
— provides wiring access
to heating controls.
18.
Flame Safeguard/Spark Generator
— monitors
flame, shuts down unit when unsafe conditions are
detected.
19.
High Limit
— prevents unit from discharging air
above a set point.
20.
Low Voltage Transformer
— reduces voltage to
Maxitrol system.
21.
Amplifier
— controls modulating valve, assures the
desired temperature is delivered.
22.
Transformer (optional)
— provides voltage to
optional evaporative cooling pump.
23.
Cooling Relay (optional)
— allows power to pass
to cooling controls.
24.
Cooling Terminal Block (optional)
— provides
wiring access to cooling controls.
25.
Low Voltage Transformer (optional)
— reduces
voltage to cooling controls.
26.
Reset Timer (optional)
— resets cooling system to
run a time interval.
27.
Auto Drain Relay (optional)
— assures supply
pump does not operate during drain interval. Allows
pump to operate in cooling mode.
28.
Cooling Timer (optional)
— allows for automatic
draining of the evaporative cooling system based
on time schedule.
Reference
Typical Control Center Layout
