Manual 2100-583G
Page
18 of 48
NOTE:
It is highly recommended on ground water
systems (pump & dump) that a cupronickel coaxial coil
is utilized on the source side of the system. Not doing
so, may void the product warranty due to aggressive/
corrosive/highly oxygenated water attacking the copper
coaxial water coil.
NOTE:
Unit shipped from factory with 75 PSIG low
pressure switch wired into control circuit for ground
water applications.
WATER CONNECTIONS
It is very important that an adequate supply of clean,
non-corrosive water at the proper pressure be provided
before installation is made. Insufficient water, in the
heating mode for example, will cause the low pressure
switch to trip, shutting down the heat pump. In assessing
the capacity of the water system, it is advisable that the
complete water system be evaluated to prevent possible
lack of water or water pressure at various household
fixtures whenever the heat pump turns on. All plumbing
to and from the unit is to be installed in accordance with
local plumbing codes. The use of plastic pipe, where
pemissible, is recommended to prevent electrolytic
corrosion of the water pipe. Because of the relatively cold
temperatures encountered with well water, it is strongly
recommended that the water lines connecting the unit be
insulated to prevent water droplets from condensing on the
pipe surface.
Refer to piping, Figure 8. Slow open/close Electrically
Actuated Valve with
End Switch
(2), 24V, provides on/off
control of the water flow to the unit. Refer to the wiring
diagram for correct hookup of the valve solenoid coil.
Constant Flow Valve
(3) provides correct flow of water
to the unit regardless of variations in water pressure.
Observe the water flow direction indicated by the arrow on
the side of the valve body.
Strainer
(8) installed upstream of
water coil inlet
to
collect foreign material which would clog the flow valve
orifice.
The figure shows the use of shutoff valves (4) and (5), on
the in and out water lines to permit isoation of the unit
from the plumbing system should future service work
require this. Globe valves should not be used as shutof
valves because of the excessive pressure drop inherent in
the valve design. Instead, use either gate or ball valves as
shutoffs, so as to minimize pressure drop.
Hose bib (6) and (7), and tees should be included to permit
acid cleaning the refrigerant-to-water coil should such
cleaning be required. See
WATER CORROSION
.
Hose bib
(1) provides access to the system to check water
flow through the constant flow valve to ensure adequate
water flow through the unit. A water meter is used to
check the water flow rate.
WELL PUMP SIZING
Strictly speaking, sizing the well pump is the
responsibility of the well drilling contractor. It is
important, however, the HVAC contractor be familiar with
the factors that determine what size pump will be required.
Rule of thumb estimates will invariably lead to under or
oversized well pumps. Undersizing the pump will result
in inadequate water to the whole plumbing system, but
with especially bad results to the heat pump - NO HEAT/
NO COOL calls will result. Oversized pumps will short
cycle and could cause premature pump motor or switch
failures.
The well pump must be capable of supplying enough
water and at an adequate pressure to meet competing
demands of water fixtures. The well pump must be sized
in such a way that three requirements are met:
1.
Adequate flow rate in GPM.
2.
Adequate pressure at the fixture.
3.
Able to meet established flow rates and pressures
from the depth of the well-feet of lift.
GROUND WATER (WELL SYSTEM APPLICATIONS)
