22
G e o t h e r m a l H e a t i n g a n d Co o l i n g
Tranquility
®
22 Digital (TZ
)
Series - 60Hz
R e v. : N o v e m b e r 1 8 , 2 0 2 2
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)
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
DXM2.5 board based on entering and leaving water
temperature (ΔT). The DXM2.5 board outputs a 0-10v signal
to determine valve position (flow 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 DXM2.5 board AND 24V power, it will
remain in the same position it was in when it lost 24V power.
NOTE:
The Cv (flow coefficient) 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 TZ024 – 060 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 flushing. Once
flushing is complete, return the valve handle to its normally
closed position.
To manually open the internal modulating motorized water
valve in TZ024 – 060, 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 flushing. Once
flushing is complete, press the lock release again and return
the valve handle to its normally closed position.
Figure 18: Internal Modulating Motorized Valve Positions
Lock Release
Sizes 026-060
Closed
Open
Lock Release
