Honeywell XE70 Series User manual

EN003-1003
XE70 SERIES T6374/T6375
FAN-COIL THERMOSTATS
4-PIPE FAN-COIL CONTROL
PRODUCT DATA
The T6374 and T6375 are designed to control the valves, or
the valves and the fan in 4-pipe fan-coil applications, with the
possibility of also being used for control of split units and
small air conditioners.
The thermostat operates the on/off valves to provide control
at the desired setpoint temperature.
The fan can also be controlled from the thermostat. It is
wired to run continuously, and can be switched off with the
system ON/OFF switch.
Versions are available with a manual 3-SPEED FAN switch,
and with a system ON/OFF switch.
Heat/cool changeover operation is also possible on some
versions. This function can be accomplished by a manually
operated HEAT/ COOL switch on the front of the thermostat,
or in some versions, automatically by means of a fixed
deadband built into the thermostat between the heating and
cooling setpoints.
FEATURES
•• Dual diaphragm sensing element ensures close
temperature control for all loads and applications
•• Attractive modern styling makes this thermostat ideal
for locating in the occupied space, particularly in
offices or hotels
•• Versions with heat anticipator, which improves
temperature control in both heating and cooling
operation
•• Thermostat mounts directly onto a wall or conduit
box
•• Slide switches allow manual control of system
operation and fan speed
•• Versions available with fixed deadband between
heating and cooling operation
•• Optional extras:
- range stops
- tamperproof cover

T6374/T6375 FAN-COIL THERMOSTATS 4-PIPE FAN-COIL CONTROL
EN003-1003 2
SPECIFICATIONS
ModelSwitches Features
ON/OFF 3-speed Fan/ Heat/Cool Heat/Cool Heat/Off/ Heat/Fan/ Fixed Auto
Fan Auto/Cont Cool Cool Deadband Change-
over
(SPST) (SPTT) (SPDT) (SPDT) (DPDT) (DPTT) (DPTT) (Aquastat)
T6374C1004 4
T6374C10124 4
T6375B101344 4
T6375B1153 4 4 4
Setpoint range
:
10...30
o
C. By means of a large setpoint
dial
Supply voltage : 230 V~, 50...60 Hz
Thermostat
switch : S.P.D.T.
Performance : Typical differential 1K (heating & cooling)
at 20oC at 50% load with anticipator
connected
Electrical ratings : 4(2) A, 230 V~
Typical loads are fans, zone valves and
relays
Operational life : Greater than 100,000 cycles (all loads)
for thermostat contacts at 230 V~
Greater than 6,000 operations for all
manually operated switches
Mounting : Mounts directly onto wall or wall-box
(mounting screws supplied)
Wiring
:
Up to 9 screw-in terminals per unit,
capable of accepting wires up to 1.5 mm2
Enclosure : Plastic 2-piece housing
Dimensions : 85 x 130 x 40 mm (w x h x d).
Protection class : IP30
RFI suppression Provided to B.S. EN 55014
Environmental
requirements
: Operating temperature range 0 to 40oC
Shipping and storage temperature range
-20 to 50oC
Humidity range 0 to 90% rh, non-
condensing
Approvals : Designed to meet harmonised EC
approvals standard IEC 730
DIMENSIONS

T6374/T637 FAN-COIL THERMOSTATS 4-PIPE FAN-COIL CONTROL5
EN003-10033
INSTALLATION
OPERATION
Sensing element
The thermostat sensing element comprises two circular,
flexible metal plates welded together at the rims and
encapsulating a gas/liquid combination whose pressure
changes in response to variations in temperature. This dual-
diaphragm expands and contracts with ambient temperature
changes to operate a snap-acting switch which controls the
heating or cooling circuit.
Heat anticipator
It is recommended that the heat anticipator is always
connected for both heating and cooling operation.
Location
The XE70 Series thermostat is the temperature control
element in the fan-coil or air-conditioning system, and must
be located in a position with good air circulation, on an inside
wall about 1.5 m above the floor to sense the average
temperature. Do not position the thermostat in draughts,
near hot or cold air sources or where it will be affected by
radiant heat from the sun or other appliances.
Mounting the thermostat
Any XE70 Series thermostat can be directly mounted on the
wall or on a conduit box (see diagram). Mounting screws are
supplied for both alternatives.
Wiring the thermostat
The standard wiring access is via a hole in the base of the
thermostat, near the top edge.
IMPORTANT
1. The installer must be a trained service engineer
2. Disconnect the power supply before beginning
installation
Switches
All switches are slide switches for ease of operation.
The ON/OFF switch is a system on/off switch, as it removes
power from the thermostat.
The FAN SPEED switch allows selection of 3 different fan
speeds, 1 (low), 2 (medium), and 3 (high)
The DPDT HEAT/COOL switch allows selection of either
heating or cooling operation. There are 2 output terminals
controlled by this switch.
The HEAT/FAN/COOL switch allows selection of either
heating or cooling operation, but also has an additional
selection position which disables all outputs except that of
the fan. The fan can be controlled separately, by the system
ON/OFF switch.
APPLICATION
T6374C T6374C T6375B T6375B
1004 1012 10131153
Ventilation
2-pipe fan-coil
Application 4-pipe fan-coil FFFF
Heatpump
Air-conditioner FFFF
Heat or Cool
Heat/cool FFFF
Control Changeover (auto or manual) auto auto manual manual
Capability Fan control (auto or cont) cont cont cont
Fan speed control F F
Valve control FFFF
Compressor control

T6374/T6375 FAN-COIL THERMOSTATS 4-PIPE FAN-COIL CONTROL
Honeywell Limited
25/F Honeywell Tower
Olympia Plaza
255 King's Road
North Point, Hong Kong
EN003-1003
ANTICIPATOR
ANTICIPATOR
ANTICIPATOR
ANTICIPATOR
HEAT
HEAT 2 HEAT 2
HEAT
COOL
COOL 2 LOAD
LOAD
LOAD
VALVE
VALVE
FAN
FAN
FAN
HEAT 1 HEAT 1
HEAT 1
HEAT 2
COOL 2
COOL 1
COOL 1
COOL 2 LOAD
LOAD
LOAD
LOAD
LOAD
COOL 1
VALVE
VALVE
LOAD
LOAD
LOAD
LOAD
FAN
COOL
WIRING
T6375B1153