Flushing The Earth Loop - Carrier 50YFV Installation, Operation And Maintenance Instructions

R e s i d e n t i a l D i g i t a l P a c k a g e d U n i t s G T- P B S e r i e s - 6 0 H z P u r o n
R e v : 4 A p r i l , 1 4

Flushing the Earth Loop

Once piping is completed between the unit and the ground
loop, fi nal purging and charging of the loop is needed.
A fl ush cart (at least a 1.5 hp [1.1kW] pump) is needed
to achieve adequate fl ow velocity in the loop to purge air
and dirt particles from the loop itself. Antifreeze solution is
used in most areas to prevent freezing. All air and debris
must be removed from the earth loop piping system before
operation, Flush the loop with a high volume of water at
a high velocity (2 fps [0.6 m/s] in all piping), using a fi lter
in the loop return line, of the fl ush cart to eliminate debris
from the loop system. See Table 17 for fl ow rate required to
attain 2fps [0.6 m/s]. The steps below must be followed for
proper fl ushing.
Table 1: Minimum Flow Required to Achieve 2 ft/sec
variety
PE Pipe Size
3/4"
1"
1 1/4"
1 1/2"
2"
Units with internal variable speed pumps also include a
check valve internal to the pump. It is not possible to fl ush
backwards through this pump. Care must be taken to
connect the fl ush cart hoses so that the fl ush cart discharge is
connected to the "water in" fl ushing valve of the heat pump.
Loop Fill
Fill loop (valve position A, see Figure 15a) with water from a
garden hose through fl ush cart before using fl ush cart pump
to ensure an even fi ll and increase fl ushing speed. When
water consistently returns back to the fl ush reservoir, switch
to valve position B (fi gure 15b).
Isolate expansion tank for fl ushing procedure using the ball
valve. During dead heading of fl ush cart pump, isolation will
prevent compression of bladder in the expansion tank and
fl ush cart fl uid level dropping below available capacity.
Figure 14a: Typical Cleanable Flush
Cart Strainer (100 mesh [0.149mm])
12
Flow (GPM)
4
6
10
13
21
WARNING!
WARNING! Disconnect electrical power source to prevent
injury or death from electrical shock.
Figure 14b: Cam Fittings for Flush Cart Hoses
Attach
to Flow
Controller
Flush Port
NOTICE: A hydrostatic pressure test is required on ALL piping,
especially underground piping before fi nal backfi ll per IGSHPA
and the pipe manufacturers recommendations.
Figure 15a: Valve Position A - Loop Fill/Flush
Out
Front of Unit
Valve Position
®
Connect
to Flush
Cart Hose
(1 of 2)
Valve Position
In
Loop