Maritime Geothermal TF-45, Installation And Service Manual

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Figure 1: Ground Loop Accessories & Tools
Ground Loop Installations
Adjust the circulator pump module valves to connect the
purge cart to the ground loop. Begin pumping water through the
ground loop, ensuring that the intake of the pump stays
submerged at all times by continuously adding water. Water
flowing back from the return line should be directed below the
water level in the barrel or flush tank to prevent air being mixed
with the outgoing water.
Refer to diagrams 000608INF & 000609INF at the end of
this section for typical ground loop configurations. They are for
reference only, and should not be used to replace formal train-
ing and computerized loop design.
Once the ground loop has been pressure tested and the
header pipes have been connected to the circulator pump mod-
ule, the heat pump can be connected to the circulator pump
module. The port connections for the Outdoor Loop are 1”
brass FPT fittings. They are marked as OUTDOOR IN and
OUT.
Circulator Pump Module
Maritime Geothermal Ltd. offers compact pump modules
with built in three way valves to facilitate filling and purging the
ground loop. Refer to drawing 000906CDG at the end of this
section. Alternatively, Grundfoss Model UPS 26-99 or Taco
Model 0011 pumps or other brands with similar pumping capa-
bility may be used. The single pump module will typically han-
dle systems up to 3 tons (model sizes 25, 35, and 45); the two
pump module will typically handle 4 to 6 ton systems (model
sizes 55, 65, 75, 80). This is based on a typical parallel system
with one circuit per ton.
Maritime Geothermal recommends calculating the total
pressure drop of the ground loop (including headers, indoor
piping and heat pump exchanger drop) based on the antifreeze
type and concentration at the desired minimum loop tempera-
ture. A pump module that can deliver the flow required for the
unit at the calculated total pressure drop should be selected.
Refer to the Model Specific Information section for unit flow re-
quirements.
Loop pressure drops can be calculated using software such
as those mentioned in the Horizontal Ground loops section, or
can be calculated in a spreadsheet using the pipe manufactur-
er’s pressure drop tables for pipe diameter and fittings.
The circulator pump module must be connected to the heat
pump Outdoor Loop ports with a lineset suitable for the flow
required with minimum pressure drop. 1” rubber or plastic lines
should be used.
The installation of P/T plugs/ports (pressure / temperature,
pronounced “
Pete’s plugs”
) is recommended on both the
entering and leaving lines at the heat pump. This will allow the
installer or homeowner to check water flow through the loop by
measuring the pressure difference through the heat exchanger
and comparing it to that listed in the Model Specific Information
section . P/T ports, adapters, and gauge adapters and are
available as accessories from Maritime Geothermal Ltd..
Flushing & Purging
Once the groundloop has been installed and all connections
are completed between the heat pump, circulator pump module
and ground loop, the entire ground loop system should be
pressure tested with air to 100 PSIG to make sure there are
no leaks on any of the inside fittings. Soap all joints and observe
that the pressure remains constant for 1 hour.
When satisfied that all connections are leak free, release
the air pressure and connect a purge cart (see Diagram B ) to
the flushing access ports at the pump module (refer to drawing
000906CDG) . A temporary flushing system can alternately be
constructed using a 45 gal. barrel and a pump with sufficient
volume and head capability to circulate fluid at a velocity of at
least 2 ft./min. through all parts of the loop.
Purge Cart
2-pump module
Barbed Adapters
PE Adapters
Gauge adapter
for P/T port
P/T port
P/T adapters for
heat pump
(1” NPT to barb)