SA-Series Technical Manual
39
Cambridge Air Solutions
REMOTE CONTROL STATION
CE-SMART
TM
SYSTEM
The CE-Smart system includes a lockable
NEMA 1 enclosure (9"W x 14"H x 5"D)
equipped with a three position selector switch
(Summer Ventilation - Off - Heating); a
combination seven day programmable timer
and thermostat (TSS); an override timer;
intermittent/continuous control; and indicating lights for
blower operation (green), burner operation (red), and
reset (amber).
The operator can control the heater from this panel
provided the heater mounted disconnect is in the “ON”
position and the service switches are in the “REMOTE”
position. The TSS utilizes an encapsulated thermistor to
sense space temperature. The adjustable differential is
set by the selection of the ON and OFF temperatures.
This control can accommodate separately programmed
schedules for both the ventilation and heating modes. See
the operating and programming instructions for the TSS
Controller (page 20).
The intermittent/continuous control allows the heater to
be operated in two modes. During unoccupied hours it
operates intermittently based on a thermostat at maxi-
mum discharge temperature (see EDL - Space Heating
Mode) for space heating. During occupied hours it oper-
ates continuously at modulating discharge temperature
for make-up air (see EDSM - Continuous Make-Up Air
Mode).
REMOTE CONTROL STATION
COMPONENTS
THERMISTOR (RTS)
The thermistor is wired to the temperature
sensor terminal block. If remote location of
the sensor is desired, the connecting cable
must be wired between the thermistor and
this point. The thermistor enclosure (SH-1)
is packed in the remote control station for
shipment. It can be mounted on the exterior sides or
bottom of the remote control station or a remote location
within 500 feet using 18 gauge stranded, twisted-pair,
shielded cable.
GAS CONTROL SYSTEM
The gas control system utilizes
Maxitrol's Series 44 modulation
controls. The discharge temperature
sensor, which is mounted in the
discharge duct, transmits a resistance
signal back to the amplifier that
corresponds to the discharge
temperature. The amplifier creates a
voltage output to drive the modulating valve to maintain
the preselected temperature.
The system can be operated either intermittently as a
space heater at maximum discharge temperature
(EDL - Space Heating Mode) or continuously as a
makeup air heater with the discharge temperature
modulating to maintain the space temperature (EDSM -
Continuous Make-Up Air Mode).
EDL - Space Heating Mode - The discharge temperature
is controlled by the MAX setting on the amplifier
(100-160˚F). The heater cycles on and off based on the
temperature settings of the space thermostat.
EDSM - Continuous Make-Up Air Mode (requires
CE-Smart) - The discharge temperature modulates to
maintain the space temperature selector. The adjustable
temperature selector is typically mounted inside the
remote control station and is set to the desired space
temperature and it transmits a resistance output to the
amplifier to control the discharge temperature. The non-
adjustable space sensor is mounted in the space and
transmits a resistance signal back to the amplifier that
corresponds to the space temperature. The discharge
temperature sensor is mounted in the discharge and
transmits a resistance signal back to the amplifier that
corresponds to the discharge temperature. The amplifier
creates a voltage output to drive the modulating valve to
maintain the selected space temperature by controlling the
heater output between the MIN and MAX setting on the
amplifier. The MIN dial setting determines the minimum
discharge temperature the heater will deliver (40 to 80˚F).
The MAX dial setting determines the maximum discharge
temperature the heater will deliver (100 to 160˚F). When
the space temperature drifts from the temperature selector
setpoint by more than 3˚F, the modulating valve is driven
to the MIN or MAX discharge temperature, as applicable.
INDIVIDUAL COMPONENT DESCRIPTIONS
