Liquid-Line Solenoid And Tubing Configuration - Bryant R-22 Application Manual And Service Manual

90° STD
90° LONG RAD
45° STD
Fig. 3—Tube Bend Losses
TABLE 5—FITTING LOSSES IN EQUIVALENT FT
REFERENCE DIAGRAM IN FIG. 1
TUBE SIZE OD
(IN.)
A
5/8 1.6
3/4 1.8
7/8 2.0
1-1/8 2.6
NOTE: If total equivalent horizontal length is 100 ft or longer,
both indoor and outdoor pistons must be increased 1 full piston
size, in addition to changes required by Tables 6 and 7.
After finding appropriate change in piston size, add or subtract the
change from original piston number. If piston size is decreased,
round new piston number down to nearest common piston number
found in Table 8. If piston size is increased, round new piston
number up to nearest common piston number found in Table 8.
A
B
C
A92498
B C
1.0 0.8
1.2 0.9
1.4 1.0
1.7 1.3
—7—
EXAMPLE:
An 042 size heat pump is 75 ft above an 042 size fan coil.
The 042 size heat-pump presale literature specifies a size
80 indoor piston and size 63 outdoor piston.
To establish correct indoor piston size for a 75 ft vertical
separation, refer to Table 6. For a 75 ft equivalent line
length, the piston change is -5. Therefore subtract 5 from
the original indoor piston size of 80:
80 – 5 = 75
Table 8 provides common piston sizes. In this instance, 75
is not listed, therefore round DOWN to next piston size,
which would be 74.
To establish correct outdoor piston size for a 75 ft vertical
separation, refer to Table 7. For a 75 ft equivalent line
length, the piston change is +4. Therefore add 4 to the
original outdoor piston size of 63:
63 + 4 = 67
Since 67 is listed in Table 8, that is the piston which should
be used. If a 67 size piston were not listed, it would be
necessary to round UP to next piston size.
TXVs may be used instead of pistons for indoor-metering devices.
Some fan coils are equipped with a hard-shutoff, bi-flow TXV
standard, and no change is required. When sizing an accessory
TXV for long-line applications, TXV should be the same nominal
tonnage as outdoor unit. Refer to presale literature for kit part
numbers.
TABLE 6—CALCULATION OF INDOOR PISTON NO.
OUTDOOR UNIT ABOVE INDOOR
FT
0-25
26-50
51-75
76-100
101-125
126-150
OUTDOOR UNIT BELOW INDOOR
FT
0-25
26-50
TABLE 7—CALCULATION OF OUTDOOR PISTON NO.
OUTDOOR UNIT ABOVE INDOOR
FT
0-50
51-75
76-100
101-125
126-150
OUTDOOR UNIT BELOW INDOOR
FT
0-50
IV. LIQUID-LINE SOLENOID AND TUBING CONFIGU-
RATION
There are 2 types of liquid-line solenoids: 1 for single-flow
applications and the other for bi-flow applications. The purpose of
having 2 solenoids is to minimize the valve internal-pressure drop
in accordance with refrigerant flow direction and liquid migration
to the compressor. The bi-flow solenoid is designed to have
minimal refrigerant-pressure drop in either flow direction, which
makes it suitable for heat pump usage. Refer to Table 9 for
liquid-line solenoid kit part numbers.
PISTON CHANGE
0
-3
-5
-7
-9
-10
PISTON CHANGE
0
+4
PISTON CHANGE
0
+4
+6
+8
+10
PISTON CHANGE
0