Service Manual

PRODUCT DESIGN
19
PROPANE GAS PIPING CHARTS
Sizing Between First and Second Stage Regulator
Maximum Propane Capacities listed are based on 1 PSIG Pressure Drop at 10
PSIG Setting. Capacities in 1,000 BTU/HR
3/8" 1/2" 5/8" 3/4" 7/8" 1/2" 3/4"
30 309 700 1,303 2,205 3,394 1,843 3,854
40 265 599 1,115 1,887 2,904 1,577 3,298
50 235 531 988 1,672 2,574 1,398 2,923
60 213 481 896 1,515 2,332 1,267 2,649
70 196 446 824 1,394 2,146 1,165 2,437
80 182 412 767 1,297 1,996 1,084 2,267
90 171 386 719 1,217 1,873 1,017 2,127
100 161 365 679 1,149 1,769 961 2,009
150 130 293 546 923 1,421 772 1,613
200 111 251 467 790 1,216 660 1,381
250 90 222 414 700 1,078 585 1,224
300 89 201 378 634 976 530 1,109
350 82 185 345 584 898 488 1,020
400 76 172 321 543 836 454 949
To convert to Capacities at 15 PSIG Settings -- Multiply by 1.130
To convert to Capacities at 5 PSIG Settings -- Multiply by 0.879
PIPE OR
TUBING
LENGTH,
FEET
NOMINAL PIPE SIZE,
SCHEDULE 40
TUBING SIZE, O.D., TYPE L
Sizing Between Single or Second Stage Regulator and Appliance*
Maximum Propane Capacities Listed are Based on 1/2" W.C. Pressure Drop at
11" W.C. Setting. Capacities in 1,000 BTU/HR
3/8" 1/2" 5/8" 3/4" 7/8" 1/2" 3/4" 1" 1-1/4" 1-1/2"
10 49 110 206 348 539 291 608 1,146 2,353 3,525
20 34 76 141 239 368 200 418 788 1,617 2,423
30 27 61 114 192 296 161 336 632 1,299 1,946
40 23 52 97 164 253 137 284 541 1,111 1,665
50 20 46 86 146 224 122 255 480 985 1,476
60 19 42 78 132 203 110 231 436 892 1,337
80 16 36 67 113 174 94 198 372 764 1,144
100 14 32 59 100 154 84 175 330 677 1,014
125 12 28 52 89 137 74 155 292 600 899
150 11 26 48 80 124 67 141 265 544 815
200 10 22 41 69 106 58 120 227 465 697
250 9 19 36 61 94 51 107 201 412 618
300 8 18 33 55 85 46 97 182 374 560
350 7 16 30 51 78 43 89 167 344 515
400 7 15 28 47 73 40 83 156 320 479
*DATA IN ACCORDANCE WITH NFPA PAMPHLET NO. 54
NOMINAL PIPE SIZE,
SCHEDULE 40
TUBING SIZE, O.D., TYPE L
PIPE OR
TUBING
LENGTH,
FEET
COOLING
The refrigerant used in the system is R-410A. It is a clear,
colorless, non-toxic and non-irritating liquid. R-410A is a
50:50 blend of R-32 and R-125. The boiling point at atmo-
spheric pressure is -62.9°F.
A few of the important principles that make the refrigeration
cycle possible are: heat always flows from a warmer to a
cooler body. Under lower pressure, a refrigerant will absorb
heat and vaporize at a low temperature. The vapors may be
drawn off and condensed at a higher pressure and tempera-
ture to be used again.
The indoor evaporator coil functions to cool and dehumidify
the air conditioned spaces through the evaporative process
taking place within the coil tubes.
NOTE: Actual temperatures and pressures are to be obtained
from the expanded ratings in the Technical Information Manual.
High temperature, high pressure vapor leaves the compres-
sor through the discharge line and enters the condenser coil.
Air drawn through the condenser coil by the condenser fan
causes the refrigerant to condense into a liquid by removing
heat from the refrigerant. As the refrigerant is cooled below
its condensing temperature it becomes subcooled.
The subcooled high pressure liquid refrigerant now leaves the
condenser coil via the liquid line until it reaches the indoor
expansion device.
As the refrigerant passes through the expansion device and
into the evaporator coil a pressure drop is experienced
causing the refrigerant to become a low pressure liquid. Low
pressure saturated refrigerant enters the evaporator coil
where heat is absorbed from the warm air drawn across the
coil by the evaporator blower. As the refrigerant passes
through the last tubes of the evaporator coil it becomes
superheated, that is, it absorbs more heat than is necessary
for the refrigerant to vaporize. Maintaining proper superheat
assures that liquid refrigerant is not returning to the compres-
sor which can lead to early compressor failure.
Low pressure superheated vapor leaves the evaporator coil
and returns through the suction line to the compressor where
the cycle begins again.
Heat Pump Models
Any time the room thermostat is switched to cool, the O
terminal is energized. This energizes the 24 volt coil on the
reversing valve and switches it to the cooling position.
When the contacts of the room thermostat close, this closes
the circuit from R to Y and R to G in the unit.
This energizes the compressor contactor and will energize
the EEM indoor blower motor after a 6-second delay.
When the thermostat is satisfied, it opens its contacts
breaking the low voltage circuit causing the compressor
contactor to open and indoor fan to stop after the programmed
60 second off delay on the EEM motor.
If the room thermostat fan selector switch should be set to the
"on" position then the indoor blower would run continuous
rather than cycling with the compressor.