Trane GEH 006 Manual page 30

Central Pumping System
Units that employ a central pumping
system contain single or dual pumps
to fulfill pumping requirements for the
entire building system.
The central system's supply and re-
turn lines should be sized to handle
the required flow with a minimum
pressure drop.
The water-source heat pump (in this
case a high efficiency GEH) may in-
clude add-on accessories to help aid in
system balancing, acoustics and safe-
ty requirements. Some of these items
may be ordered from the factory, then
field installed. Many are provided by
the contractor.
1
Hose kits are used to connect the
water supply and return line to the
water inlets and outlets. Trane of-
fers various hose kit combina-
tions to better facilitate
system flow balancing.
These flexible hoses also aid
in the reduction of vibration
between the unit and the rig-
id central piping system.
A two position isolation valve is
often applied to systems which in-
corporate variable frequency
pumping. This valve is capable of
stopping/starting water flow to the
unit, which in-turn reduces
the pumping requirements
for the entire system.
2
The unit's (item 2) 3/4-inch high
3
voltage and (item 3) 1/2-inch low
voltage connections are located
on the left chamfered corner
of the unit. They are de-
signed to accept con-
duit.
4
A field supplied line voltage dis-
connect should be installed for
branch circuit protection. Check
local codes for requirements.
30
Application
Considerations
5 The central system supply and
return lines should be sized to
handle the required flow with a
minimum pressure drop.
Note: Pipe will sweat if low tem-
perature water is below the dew
point of the surrounding space.
Trane recommends that these
lines be insulated to prevent dam-
age from condensation when con-
denser loop is designed to be
below 60 F.
6
For acoustically sensitive areas, a
six-inch deep fiberglass insula-
tion is recommended to be field
installed below the horizontal unit.
This field supplied insulation
should be approximately twice the
footprint size of the unit. It pro-
vides sound damping of the unit
while in operation.
WSHP-PRC001-EN