20
G e o t h e r m a l H e a t P u m p S y s t e m s
P R E L I M I N A RY
Tranquility
®
30 Digital (TE) Series IOM - 60Hz HFC-410A
R e v. : 3 A u g . , 2 0 1 2 B
Closed Loop - External Central Pumping Applications
High and
Low Voltage
Knockouts
Vibration Isolation Pad
To Thermostat
Internal Motorized
Modulating Valve
Water Out
Shut Off
Ball Valves
for Isolation
Water In
Figure 17: Typical Closed Loop with Central Pumping Application (with Internal Modulating Motorized Valve Shown)
/RFN5HOHDVH
Sizes 026-049
Sizes 064-072
Closed
Closed
Open
Open
Figure 18: Internal Modulating Motorized
Valve Positions
Tranquility Digital packaged units are available with a
modulating water valve option for closed-loop applications
with external central pumping (designated by a 5 in the 11th
position of the unit model number). With this option, the
Modulating Valve is regulated by the Communicating DXM2
board based on entering and leaving water temperature (
∆
T).
The DXM2 board outputs a 0-10v signal to determine valve
position (
fl
ow rate). The modulating valve defaults to closed
position if it loses signal but still has 24V power running to
it. If the motorized modulating valve loses both signal from
the DXM2 board AND 24V power, it will remain in the same
position it was in when it lost 24V power.
Note: The Cv (
fl
ow coef
fi
cient) of the valve used in these
units is DIFFERENT that the Cv of the valve used in the
open loop unit. It is not advisable for use in open loop
applications as sound/noise issues may result. Units with
the water circuit for closed loop, central pumping option are
only available with a copper water coil.
To manually open the internal modulating motorized water
valve in TE026 – 049 push down on the handle to unlock
it. Then rotate the handle to the open position as shown
in Figure 18. This fully opens the valve for
fl
ushing. Once
fl
ushing is complete, return the valve handle to its normally
closed position.
To manually open the internal modulating motorized water
valve in TE064 – 072, push down on the lock release button
while turning the handle to the open position as shown in
Figure 18. This fully opens the valve for
fl
ushing. Once
fl
ushing is complete, press the lock release again and return
the valve handle to its normally closed position.