Antifreeze; Cooling Tower/Boiler Systems; Ground Coupled, Closed Loop And Plateframe Heat Exchanger Well Systems; Operation - Carrier Aquazone 50HQP Series Installation, Start-Up And Service Instructions Manual

After pressurization, be sure to remove the plug from the end
of the loop pump motor(s) to allow trapped air to be discharged
and to ensure the motor housing has been flooded. Be sure
the loop flow center provides adequate flow through the unit
by checking pressure drop across the heat exchanger.

Antifreeze

In areas where entering loop temperatures drop below 40°F or
where piping will be routed through areas subject to freezing, anti-
freeze is needed.
Alcohols and glycols are commonly used as antifreeze agents.
Freeze protection should be maintained to 15°F below the lowest
expected entering loop temperature. For example, if the lowest ex-
pected entering loop temperature is 30°F, the leaving loop tem-
perature would be 22 to 25°F. Therefore, the freeze protection
should be at 15°F (30°F – 15°F = 15°F).
IMPORTANT: All alcohols should be pre-mixed and
pumped from a reservoir outside of the building or intro-
duced under water level to prevent alcohols from fuming.
Calculate the total volume of fluid in the piping system. See
Table 7. Use the percentage by volume in Table 8 to determine the
amount of antifreeze to use. Antifreeze concentration should be
checked from a well mixed sample using a hydrometer to measure
specific gravity.
Table 7 — Approximate Fluid Volume (gal.)
per 100 Ft of Pipe
PIPE DIAMETER (in.)
1
Copper
1.25
1.5
Rubber Hose
1
3 / IPS SDR11
4
1 IPS SDR11
1 /
1
4
/ IPS SDR11
1
Polyethylene
2
2 IPS SDR11
1 1 /
4
1 1 /
2
2 IPS SCH40
LEGEND
IPS — Internal Pipe Size
SCH — Schedule
SDR — Standard Dimensional Ratio
NOTE: Volume of heat exchanger is approximately 1.0 gallon.
Table 8 — Antifreeze Percentages by Volume
ANTIFREEZE
Methanol (%)
100% USP Food Grade
Propylene Glycol (%)
Ethanol (%)

Cooling Tower/Boiler Systems

These systems typically use a common loop maintained at 60 to
90°F. The use of a closed circuit evaporative cooling tower with a
secondary heat exchanger between the tower and the water loop is
recommended. If an open type cooling tower is used continuously,
chemical treatment and filtering will be necessary.
VOLUME (gal.)
4.1
6.4
9.2
3.9
2.8
4.5
IPS SDR11 8.0
10.9
18.0
IPS SCH40 8.3
IPS SCH40 10.9
17.0
MINIMUM TEMPERATURE FOR
FREEZE PROTECTION (F)
10 15 20
25 21 16
38 30 22
29 25 20
Ground Coupled, Closed Loop and Plateframe
Heat Exchanger Well Systems
These systems allow water temperatures from 30 to 110°F. The
external loop field is divided up into 2 in. polyethylene supply and
return lines. Each line has valves connected in such a way that
upon system start-up, each line can be isolated for flushing using
only the system pumps. Air separation should be located in the
piping system prior to the fluid re-entering the loop field.

Power Up Mode

The unit will not operate until all the inputs, terminals and safety
controls are checked for normal operation.
NOTE: The compressor will have a 5-minute anti-short cycle
upon power up.
Units with Aquazone™ Complete C Control

STANDBY

Y and W terminals are not active in Standby mode. However, the
O and G terminals may be active, depending on the application.
The compressor will be off.

COOLING

Y and O terminals are active in Cooling mode. After power up, the
first call to the compressor will initiate a 270 to 300 second ran-
dom start delay and a 5-minute anti-short cycle protection time de-
lay. After both delays are complete, the compressor is energized.
NOTE: On all subsequent compressor calls the random start delay
is omitted.

HEATING STAGE 1

Terminal Y is active in heating stage 1. After power up, the first
call to the compressor will initiate a 270 to 300 second random
start delay and a 5-minute anti-short cycle protection time delay.
After both delays are complete, the compressor is energized.
NOTE: On all subsequent compressor calls the random start delay
is omitted.
HEATING STAGE 2
To enter Stage 2 mode (units equipped with 2 step compressor or
with two compressors only), terminal Y2 is active (Y is already
active). Also, the G terminal must be active or the W terminal is
disregarded. The compressor relay will remain on and EH1 is im-
mediately turned on. EH2 will turn on after 10 minutes of continu-
al stage 2 demand.

LOCKOUT MODE

The status LED will flash fast in Lockout mode and the compres-
25
sor relay will be turned off immediately. Lockout mode can be
10 "soft" reset via the Y input or can be reset via the disconnect de-
pending on the DIP switch settings. The last fault causing the
15
lockout is stored in memory and can be viewed by entering test
14
mode.

LOCKOUT WITH EMERGENCY HEAT

While in Lock-out mode, if W becomes active, then Emergency
Heat mode will occur.

EMERGENCY HEAT

In Emergency Heat mode, terminal W is active while terminal Y
is not. Terminal G must be active in the 50HQP,VQP units; the fan
will be run if W is energized. EH1 is immediately turned on. EH2
will turn on.
38

OPERATION