Carrier 50YFV Installation, Operation And Maintenance Instructions page 19

R e s i d e n t i a l D i g i t a l P a c k a g e d U n i t s G T- P B S e r i e s - 6 0 H z P u r o n
10 gallons [37.9 liters] total. If more than one tankful is
required, the tank should be drained immediately by
opening the waste valve of the fl ush cart noting the
color of the discharge fl uid. Adding food coloring to the
antifreeze can help indicate where the antifreeze is in the
circuit and prevents the dumping of antifreeze out the
waste port. Repeat if necessary.
5) Be careful when handling methanol (or any alcohol).
Always wear eye protection and rubber gloves. The
fumes are fl ammable, and care should be taken with all
fl ammable liquids. Open fl ush valves to fl ush through
both the unit and the loop and fl ush until fl uid is
homogenous and mixed. It is recommended to run the
unit in the heating and cooling mode for 15-20 minutes
each to 'temper' the fl uid temperature and prepare it for
pressurization. Devoting this time to clean up can be
useful. This procedure helps prevent the periodic "fl at"
loop condition.
6) Close the fl ush cart return valve; and immediately
thereafter, close the fl ush cart supply valve, leaving a
positive pressure in the loop of approximately 50 psi [345
kPa]. This is a good time to pressure check the system
as well. Check the freeze protection of the fl uid with the
proper hydrometer to ensure that the correct amount of
antifreeze has been added to the system. The hydrometer
can be dropped into the fl ush reservoir and the reading
compared to Chart 1a for Methanol, 1b for Propylene
Glycol, and 1c for Ethanol to indicate the level of freeze
protection. Do not antifreeze more than a +10°F [-12.2°C]
freeze point. Specifi c gravity hydrometers are available
in the residential price list. Repeat after reopening and
fl ushing for a minute to ensure good second sample
of fl uid. Inadequate antifreeze protection can cause
nuisance low temperature lockouts during cold weather.
WARNING!
WARNING! Always dilute alcohols with water (at least 50%
solution) before using. Alcohol fumes are fl ammable and
can cause serious injury or death if not handled properly.
When handling methanol (or any alcohol), always wear
eye protection and rubber gloves as alcohols are easily
absorbed through the skin.
7) Close the fl ush cart return valve; immediately thereafter,
close the fl ush cart supply valve, shut off the fl ush cart
leaving a positive pressure in the loop of approximately
50-75 psi [345-517 kPa]. Refer to Figure 15e for more
details.
Low Water Temperature Cutout Setting - DXM2 Control
When antifreeze is selected, the LT1 jumper (JW3) should
be clipped to select the low temperature (antifreeze 10°F
[-12.2°C]) set point and avoid nuisance faults (see "Low
Water Temperature Cutout Selection" in this manual).
Ground Loop Applications
Chart 1a: Methanol Specifi c Gravity
1.000
0.995
0.990
0.985
0.980
0.975
0.970
0.965
0.960
-50°F -40°F -30°F -20°F -10°F
-45.6°C -34.4°C -23.3°C
-40°C -28.9°C -17.8°C
Low Temperature Protection
Chart 1b: Propylene Glycol Specifi c Gravity
1.07
1.06
1.05
1.04
1.03
1.02
1.01
1.00
-40°F -30°F -20°F -10°F 0°F
-40°C -34.4°C -28.9°C -23.3°C -17.8°C -12.2°C -6.7°C
Low Temperature Protection
Chart 1c: Ethanol Specifi c Gravity
1.000
0.995
0.990
0.985
0.980
0.975
-5°F 0°F 5°F 10°F 15°F
-20.6°C -17.8°C -15.0°C -12.2°C -9.4°C
Low Temperature Protection
Figure 17: Low Temperature Cutout Selection
Off On
JW3
Off On
S3
Off On
S2
c1
ay
A0-1 A0-2
S1
c2
ay
P10
P11
O1 Gnd Gnd T1 T2 T2 T3 T3 T4 T4
AO2
JW3-LT1 jumper should be clipped
for low temperature operation
R e v : 4 A p r i l , 1 4
0°F 10°F 20°F 30°F 40°F 50°F
-12.2°C -1.1°C 10°C
-6.7°C 4.4°C
10°F 20°F 30°F 40°F
-1.1°C 4.4°C
20°F 25°F 30°F 35°F
-6.7°C -3.9°C -1.1°C 1.7°C
LT2
LT2
RV
RV
CO
12
CO
P7
RV
Relay
CCH 1
24Vdc
Relay
EH1
4
EH2
P6
Comp
Relay
CCG
CC
P9
T5 T5 T6 T6
DXM2 PCB
®
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