Specifications

GT-PCS Split Units - 60Hz Puron
®
Created: 29 Aug., 2013
12
Figure 8b: Valve Position B - Unit Fill / Flush
Loop
Valve Position
Out
In
Flushing the Earth Loop
Flush Port
Front of Unit
Valve Position
Figure 8d: Valve Position C - Full Flush
Loop
Valve Position
Dead Head
Pump Test
for Air
Add Antifreeze
Now if Needed
Out
In
Flush Port
Front of Unit
Valve Position
Unit Fill
Unit fi ll valves should be switched to Position B while fl ush
cart is pumping to fi ll the unit heat exchanger (see Figure
8b). The valves position should be maintained until water is
consistently returned into the fl ush reservoir.
Loop Flush
Switch to valve Position A. The supply water may be shut off
and the fl ush cart turned on to begin fl ushing. Once the fl ush
reservoir is full, do not allow the water level in the fl ush cart
tank to drop below the pump inlet line or air can be pumped
back out to the earth loop. Try to maintain a fl uid level in the
tank above the return tee so that air can not be continuously
mixed back into the fl uid. Surges of 50 psi [345 kPa] can
be used to help purge air pockets by simply shutting off
the fl ush cart return valve going into the fl ush cart reservoir.
This process ‘dead heads’ the pump to 50 psi [345 kPa]. To
dead head the pump until maximum pumping pressure is
reached, open the valve back up and a pressure surge will
be sent through the loop to help purge air pockets from the
piping system. Notice the drop in fl uid level in the fl ush cart
tank. If all air is purged from the system, the level will drop
only 3/8” in a 10” [25.4 cm] diameter PVC fl ush tank (about
a half gallon [1.9 liters]) since liquids are incompressible. If
the level drops more than this level, fl ushing should continue
since air is still being compressed in the loop fl uid. Do this a
number of times.
NOTICE: Actual fl ushing time require will vary for each
installation due to piping length, confi guration, and fl ush
cart pump capacity. 3/8” or less fl uid level drop is the ONLY
indication that fl ushing is complete.
Switch valves to Position B to fl ush the unit. Flush through
the unit until all air pockets have been removed.
Move valves to position C. By switching both valves to this
position, water will fl ow through the loop and the unit heat
exchanger. Finally, the dead head test should be checked
again for an indication of air in the loop. Fluid level drop is
your only indication of air in the loop.
Pressurize and Operate
As shown in Figure 8e, close the fl ush cart return valve
to pressurize the loop to at least 50 psi [345 kPa], not to
exceed 75 psi [517 kPa]. Open the isolation valve to the
expansion tank and bleed air from the expansion tank piping
using the schraeder valve located in front of the expansion
tank. This will allow loop pressure to compress the
expansion tank bladder, thus charging the expansion tank
with liquid. After pressurizing, close the fl ush cart supply
valve to isolate the fl ush cart. Move the Flow Controller
valves to Position D.
Loop static pressure will fl uctuate with the seasons and
pressures will be higher in the winter months than during
the cooling season. This fl uctuation is normal and should
be considered when charging the system initially. Unhook