Cambridge Air Solutions.
90
M-Series Technical Manual
Manual Make-Up Air Switch (MMS)
A manual make-up air toggle switch is used to manually
turn the heater on and off. It is either mounted on the
exterior of the door of the Remote Control Station
or mounted inside the Remote Control Station for
tamperproof applications.
Exhaust Fan Interlock (EFI)
An exhaust fan interlock is used to interlock the make-
up air heater as a slave to an exhaust fan. Terminals are
provided in the Remote Control Station for wiring of dry
contacts (by others).
THERMISTOR SENSOR
The thermistor enclosure is packed inside the Remote
Control Station for shipment. It can be mounted on the
exterior sides or bottom of the Remote Control Station
(see Figure 1). It can also be mounted in a remote loca-
tion within 500 feet of the Remote Control Station using
18 gauge stranded, twisted-pair, shielded cable. The
thermistor is wired to the TEMP. SENSOR terminal
block on the thermostat.
THERMISTOR INSTALLATION
(See Figure 2)
1. Insert the star bushing through the opening in the
enclosure.
2. Run the thermistor leads through the star bushing.
3. Attach the cover to the enclosure over the thermistor
sensor.
4. Separate and strip the ends of the lead wires 3/8".
5. Open the terminal blocks for the sensor connections.
6. Insert the lead wires and close the terminal blocks to
the locked position.
NOTE: For remote sensors connected with shielded
cable, ground the shield at the thermostat end only.
TEMPERATURE AVERAGING (TAS-2)
OPTION
(See Figure 3)
The TAS-2 option allows one thermostat to have two
sensing locations. Each enclosure has two thermistor
sensors prewired in series (see A). The sensor leads are
then connected to the thermostat in parallel (see B). The
thermostat display will show the average of the tempera-
tures at the two sensing locations. The TAS-2 is a unique
application. Consult the design drawing and/or your
Cambridge Representative for placement assistance.
Figure 2
Figure 3
Figure 1
Figure 2
Figure 3
Figure 1
Figure 2
Figure 3
Figure 1
