Step 7 - Pipe Connections; Water Quality Guidelines; Units With Waterside Economizer Or Boilerless Heat Control; Well Water Systems (50°F Ewt [Entering Water Temperature] Minimum) - Carrier Aquazone VQP 072 Installation, Start-Up And Service Instructions Manual

Fig. 15 — Condensate Trapping
A second trap must not be included. The horizontal unit should be
pitched approximately 1/4-in. towards the drain in both directions,
to facilitate condensate removal. (See Fig. 16.)
Fig. 16 — Sloped Horizontal Unit Installation
Step 7 — Pipe Connections
Supply and return piping must be as large as the unit connections
on the heat pump (larger on long runs). Never use flexible hoses of
a smaller inside diameter than that of the water connections on the
unit. Units are supplied with either a copper or optional
cupronickel coaxial water coil. Copper is adequate for ground wa-
ter that is not high in mineral content. Should your well driller ex-
press concern regarding the quality of the well water available or
should any known hazards exist in your area, Carrier recommends
proper testing to assure the well water quality is suitable for use
with water source equipment. In conditions anticipating moderate
scale formation or in brackish water a cupronickel heat exchanger
is recommended.
Both the supply and discharge water lines will sweat if subjected
to low water temperature. These lines should be insulated to pre-
vent damage from condensation.
All manual flow valves used in the system must be ball valves.
Globe and gate valves must not be used due to high pressure drop
and poor throttling characteristics. Never exceed the recommend-
ed water flow rates. Serious damage or erosion of the water to re-
frigerant heat exchanger could occur.
Always check carefully for water leaks and repair appropriately.
Units are equipped with female pipe thread fittings. Consult the
specification sheets for sizes. Teflon
when connecting water piping connections to the units to insure
against leaks and possible heat exchanger fouling. Do not
overtighten the connections. Flexible hoses should be used be-
tween the unit and the rigid system to avoid possible vibration.
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owners.
Condensate Drain
Connection
Vent (Optional)
Slope Down
Min. 1/8"
Per Foot
Trap Down
2" Min.
1/4"
tape sealer should be used
1
Ball valves should be installed in the supply and return lines for
unit isolation and unit water flow balancing.
Pressure/temperature ports are recommended in both the supply
and return lines for system flow balancing. The water flow can be
accurately set by measuring the water-to-refrigerant heat exchang-
ers water side pressure drop. See the unit specification sheets for
the water flow and pressure drop information.

WATER QUALITY GUIDELINES

In all applications, the quality of the water circulated through the
heat exchanger must fall within the ranges listed in Table 2, Water
Quality Guidelines. Consult a local water treatment firm, indepen-
dent testing facility, or local water authority for specific recom-
mendations to maintain water quality within the published limits.
UNITS WITH WATERSIDE
BOILERLESS HEAT CONTROL
Units with Complete C or Deluxe D controls and waterside econo-
mizer or units with Boilerless Heat Control (all Deluxe D) include
an aquastat with remote sensing bulb that must be field-installed
on the incoming water piping. The remote sensing bulb must be
installed on a straight section of uninsulated pipe that provides a
good measurement of the entering water temperature. It is recom-
mended to insulate the sensing bulb after installation for better
water temperature sensing.
Water piping exposed to extreme, low ambient temperatures is
subject to freezing.
WELL WATER SYSTEMS (50°F EWT [ENTERING
WATER TEMPERATURE] MINIMUM)
When a water well is used exclusively for supplying water to the
heat pump, the pump should operate only when the heat pump
operates. A 24 volt, double-pole single-throw contactor can be
used to operate the well pump with the heat pump.
When two or more units are supplied from one well, the pump can
be wired to operate independently from either unit. Two 24-volt
double-pole single-throw relays wired in parallel are required. An
upsized VA transformer may be required in either case.
The discharge water from the heat pump is not contaminated in
any manner and can be disposed of in various ways depending on
local codes (e.g., discharge well, dry well, storm sewer, drain field,
stream, pond, etc.).

COOLING TOWER/BOILER APPLICATION

To ensure adequate cooling and heating performance, the cooling
tower and boiler water loop temperature should be maintained be-
tween 50°F and 80°F in the heating mode and 70°F and 110°F in
the cooling mode. In the cooling mode, heat is rejected from the
unit into the water loop. A cooling tower provides evaporative
cooling to the loop fluid, thus maintaining a constant supply tem-
perature to the unit. When utilizing an open cooling tower, chemi-
cal water treatment is mandatory to ensure the water is free of cor-
rosive materials.
A secondary heat exchanger (plate frame between the unit and the
open cooling tower) may also be used. It is imperative that all air
is eliminated from the closed loop side of the heat exchanger to
prevent condenser fouling. In the heating mode, heat is absorbed
from the water loop to the unit. A boiler can be utilized to maintain
the loop within the proper temperature range.
No unit should be connected to the supply or return piping until
the water system has been completely cleaned and flushed to re-
move dirt, piping chips or other foreign material. Supply and re-
turn hoses should be connected together during this process to en-
sure the entire system is properly flushed. After the cleaning and
flushing has taken place the unit may be connected to the water
loop and should have all valves wide open. See Fig. 17.
16
ECONOMIZER
CAUTION
OR