48
WSHP-SVX01Y-EN
Condensate Drain Connection
Figure 50.
Negative pressure system
CLEAN OUT
(CAPPED and SEALED)
Install proper trapping to the equipment. The unit drain
connection is 0.75 in. NPT for all GEV 0.5 to 25 ton and
GEH 0.5 to 5 ton models. For 6 to15 ton GEH models,
the drain connection is 0.5 in. PVC schedule 40 pipe.
When designing the condensate trap for the water-
source system, it is important to consider the unit
draw-thru design requiring negative pressure trapping.
In a properly trapped system, when condensate forms
during normal operation, the water level in the trap
rises until there is a constant flow. It is imperative to
maintain water in the trap and not allow the trap to dry
out during heating season. Keeping trap primed at all
times will enable the water to flow properly. See the
figure above for appropriate dimensions required in a
negative pressure system.
Supply Pipe Connections
Figure 51.
Supply/return pipe connections
RETURN
TO
LOOP
SUPPLY
FROM
CENTRAL
PUMP
AUTOMATIC BALANCING
HOSE KIT
WATER-IN
WATER-OUT
Connect the supply and return hoses to the water-inlet
(from supply) and water-outlet (to return) of the unit.
For vibration isolation, it is recommended that flexible
steel braided hoses be installed instead of hard piping
the equipment to the main loop system. Figure above
shows connection of a Hays Mesurflo® balancing hose
kit to the water-in and water-out of a vertical unit.
N
No
otte
e:: Above figure example incorporates the Hays
Mesurflo® balancing hose kit and a 2-position
isolation valve into the system design. An
isolation valve is often used in variable speed
pumping applications. The isolation valve is
designed to stop water flow to the unit during
non operation times. This allows the loop water
pumps to run only when a requirement for
pumping is needed for greater energy efficiency
of the overall system design.
Cleaning and Flushing the Water
Loop
After the piping system is complete, the flexible hose
connectors should be doubled back to complete the
water circuit external to the unit (avoiding trash settle-
out in the condenser). An extra pipe may be necessary
to connect the hose kits.
1. Water circulation system should be filled with clean
water using the water make up connections.
N
No
otte
e:: Air vents should be open during filling.
2. With the air vents closed, start the circulating pump
and then crack the air vents to bleed off the trapped
air, assuring circulation through all components of
the system.
N
No
otte
e:: Make up water must be available to the system
to replace the volume formerly occupied by the
air that is bled off.
3. With the air vented and the water circulating, the
entire system should be checked for leaks with
repairs made as required.
4. Operate the supplementary heat system (boiler)
making checks per manufacturer’s instructions.
During this operation, visual checks should be
made for leaks that may have occurred due to
increased heat. Repair as required.
5. Open the system at the lowest point for the initial
blow down (making sure the make up water is
equal to the water being dumped). Continue blow
down until the water leaving the drain runs clear,
but not less than 2 hours.
6. Shut down pumps and supplementary heat system.
Reconnect the hoses placing the water-to-
refrigerant heat exchanger in the water circulating
system.
N
No
otte
e:: Vents should be open when the pumps and
supplementary heat system are shut down.
Summary of Contents for Axiom GEH-E035
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