33
IOM, ZS/ZT Models
Enertech Global
open to all 3 ports, the unit, loop, and flush
port. Turn the other valve so it is only open
to the loop and flush port (pressure is also
applied to the hose kit in this arrangement).
2. Turn the flush cart pump on and allow the
system to start circulating.
3. With the pump running, turn the return line
ball valve to the off position on the flush
cart, “dead heading” the pump.
4. There should be a maximum of 1” to 2”
inches of drop in the water level in the
reservoir. This only takes about 3-5 seconds.
5. Next, turn the supply line ball valve to the off
position on the flush cart (isolates the flow
center from the flush cart).
6. Now that the system is isolated from the
reservoir the pump can be turned off. Do
not open the main flush cart ball valves yet.
7. Connect the water supply back to the
discharge line hose connection, and open
the ball valve. Turn on the water supply
and leave it on for 20 to 30 minutes. This
will stretch the pipe properly to insure that
the system will not have a “flat” loop during
cooling operation.
8. Once the loop is pressured (recommended
pressure on initial start up is 50 to 70 psi), turn
the water supply off. Turn off the discharge
line ball valve, and disconnect the water
supply. Maximum pressure should never
exceed 100 psi under any circumstance!
9. Turn the 3-way valves on the flow center
back to the normal operation mode, which
closes the flush port connections.
10. Open the ball valves on the flush cart to
relieve pressure on the hoses. Disconnect the
hoses from the flow center.
Note: Pressurized flow centers and Grundfos UP
series pumps need a minimum of 3psi on the
suction side of the pump to operate. Maximum
operating pressure is 100 psi.
Loop static pressure will fluctuate with the
seasons. Pressures will be higher in the winter
months than during the summer months. In
the cooling mode the heat pump is rejecting
heat, which relaxes the pipe. This fluctuation
is normal and needs to be considered when
charging and pressuring the system initially.
Typical operating pressures of an earth loop are
15 to 50 psi.
Note - Burping pump(s): On flow center initial
start up, the pumps must be bled of air. Start
the system and remove the bleed screw from
the back side of the pump(s). This allows any
trapped air to bleed out. It also floods the
pump shaft, and keeps the pump(s) cool.
Failure to do this could result in premature
pump failure.
Flushing the Interior Piping (Non-Pressurized)
Do not use the flush cart to purge the interior
piping and flow center in a non-pressurized
system. Once the loop has been flushed the
ball valves may be opened above the flush
ports. Take a garden hose from the flush port
connected to the water out to the loop pipe,
and run the other end of the hose into the top
of the canister. Fill the canister with water and
turn the pumps on. Continue to fill the canister
until the water level stays above the dip tube.
Once filling is complete, remove the hose and
close the flush port. Turn the system on. Any air
that may still be in the system will burp itself out
of the top of the canister. Leave the top open
for the first 1/2 hour of run time to ensure that
all of the air is bled out. Tighten the cap on the
flow center to complete the flushing and filling
procedure (hand tighten only -- do not use a
wrench).
Condensation Drain Connection
Follow all local plumbing codes. Connecting
the EZ-Trap (ACDT1A - EZ-Trap ¾” Kit, ACDT2A -
EZ-Trap 1” Kit) to the condensate drain requires
a minimum 6 1/2 inches of vertical clearance.
The drain must be pitched away from the unit
a minimum of 1/4” per foot. For full instructions
see EZ-Trap Kit installation sheet.
Condensation Drain Connection Example
1.0"
EZ-Trap
6 1/2"
1/4" per foot
Secondary Drain
Pan (Optional)
6 1/2" vertical clearance required
Unit Equipment
Pad
SECTION 5: UNIT PIPING INSTALLATION