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Figure 2 - Mounting Dimensions
W7082A, W7083A, W7084A Units in Inch [mm In
brackets]
Nonspring
Return
Motors - M734J, M744D have a solid
state balance relay, operate on 24 Vac, 50/60 Hr.
Spring Return Motors - M746G,K,L,P motors have solid-
state balance
relay, require separate 24 Vac, 50/60
power supplies.
Time Delay Relays - To improve stability of the system
and minimize energy use, five minute turn on time delays
should be added to all heating and cooling loads. These
relays should be wired between cooling and heating stage
switching outputs (W7080A Load Analyzer W7083A Electric
Heat Sequencer
and 1953258 Fourth Stage Cooling Board)
and the heating and cooling equipment.
SYSTEM
ACCESSORIES:
Transformers: AT20-20 VA; AT7240 VA; A T 8 8 - 7 5 VA
for W7080A
Hz
Analyzer can also be used to power stage relays in the
W7083A
Electric Heat Sequencer
and M745 motors each require a separate transformer to
ensure electrical
isolation. 'NEVER G R O U N D THE
SECONDARY OF ANY TRANSFORMER USED TO
POWER ANY SYSTEM COMPONENT.
Q209A Minimum Position Potentiometer
iy on M734, M744, M745 motors; controls minimum open
position of damper.
Q605 Damper Linkage - Connects motor to damper. in-
cludes motor crank arm.
Q618 Valve Linkage - Connects Modutrol motor to
modulating hot or chilled water valves.
S963A Remote Mlnlmum PositIon Potentiometer
Provides
remote manual control of minimum open position
of economizer motor.
Modulatlng Water Valves - Use appropriate valve with
Super Modutrol motor and Q618 Linkage to provide propor-
tional control of hot or chilled water flow.
Compressor Ambient Lockout Thermostat - Use with
direct expansion cooling system to prevent compressor
operation
when outdoor air temperature falls below
economizer setpoint.
-
T675A Temperature Control l e r.
-
L6018C Temperature Controller.
Economizer Changeover
at minimum position whenever outdoor air temperature or en-
thalpy is above controller setpoint.
-
H205A1038 or H205A1046 Enthal p y Control l e r.
-
T675A
Nlght Setback - Provides
[3.3 to 12.2°C]. Requires connection
S6005 Time Clock contact conncected between Terminals 3,
7 or 6; and 5 of T7080A or T7080B Thermostat.
-
T675A Tsn~ cammu=
-
S43 Sail Switch - Activates circuits when minimum airflow
is maintained in duct. Deactivates circuit below minimum
airflow.
1914448 Metal Cover - Designed to protect the W7080A,
W7081A, W7082A, W7083A and W7084A components when
mounted on open surface. Overall dimensions of units with
metal cover in place: 6% in. long, 4+'1'16 in. wide, 49'w in.
high [168.3 x 108.5 x 122.2 mm].
4
(if used). The M744
- Mounts direct-
-
Controller - Holds economizer
heating setback of 6 to 22°F
of a 1% resistor and
I
I
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