Closed Loop Heat Pump Applications With Internal Flow Controller - ClimateMaster Trilogy Q-Mode (QE) Series Manual

Closed Loop Heat Pump Applications with Internal Flow Controller

Units with internal flow control come with a built-in variable
speed pump, an expansion tank, flushing ports and three-
way valves (used to flush the unit). The variable speed
pump is controlled by the EXM board based on the difference
between the entering and leaving water temperature
(ΔT). For operation outside of the normal entering water
temperature range (50° or 60°F - 110°F for cooling,
30°F-70°F for heating) the EXM controller automatically
adjusts the control ΔT to account for the abnormal entering
water temperatures, maintaining an appropriate flow rate for
proper unit operation. When entering water temperatures
are abnormally low for cooling, or abnormally high for
heating, the EXM controller will maintain suction and
discharge pressures within the normal operating envelope of
the compressor which will allow the unit to operate properly
under those conditions. The internal expansion tank helps
to maintain constant loop pressure despite the natural
expansion and contraction of the loop as the seasons and
loop temperatures vary to help avoid flat loop callbacks.
Pre-Installation
Prior to installation, locate and mark all existing underground
utilities, piping, etc. Install loops for new construction before
sidewalks, patios, driveways, and other construction has
begun. During construction, accurately mark all ground loop
piping on the plot plan as an aid in avoiding potential future
damage to the installation.
Piping Installation
The typical closed loop ground source system is shown in
Figures 6 and 11. All earth loop piping materials should be
limited to polyethylene fusion only for in-ground sections of the
Figure 12: Internal Flow Controller
Trilogy Q-Mode (QE) Series IOM - 60Hz HFC-410A
® ®
loop and it is also recommended for inside piping. Galvanized
or steel fittings should not be used at any time due to their
tendency to corrode. All plastic to metal threaded fittings
should be avoided due to their potential to leak in ground loop
applications. Loop temperatures can range between 25 and
110°F [-4 to 43°C]. Flow rates between 2.25 and 3 gpm
per ton [2.41 to 3.23 l/m per kW] of cooling capacity is
recommended in these applications.
Test individual horizontal loop circuits before backfilling.
Test vertical U-bends and pond loop assemblies prior to
installation. Pressures of at least 100 psi [689 kPa] should be
used when testing the ground loop. Do not exceed the pipe
pressure rating. Test entire ground loop when all loops are
assembled.
Never exceed 100 psig pressure in a Trilogy unit.
Exceeding 100 psig in a Trilogy unit will damage the
internal pressure sensor. If pressure greater than 100 psig
are desired for loop/piping testing the Trilogy unit must be
isolated from that pressure by manual shut-off valves during
pressure testing.
The following section will help to guide you through flushing a
unit with internal flow control.
NOTICE! If installing MULTIPLE vFlow
Speed Flow Controller units (in parallel) on one loop,
please refer to section 'Multiple Unit Piping and Flushing'
(later in this document).
c l i m a t e m a s t e r . c o m
R e v i s e d : D e c e m b e r 2 2 , 2 0 2 1
⚠ ⚠
NOTICE!
Internal Variable
®
13