Bryant 569J Series Installation, Start-Up And Service Instructions Manual page 15

Suction Riser —
A suction riser condition exists when the outdoor unit is
located above the indoor (evaporator) unit and suction
vapor must flow vertically up to return to the compressor.
Oil return is a concern when the suction tube size is too
large to produce the minimum refrigerant velocity to
ensure oil return at minimum load conditions.
569J***A/B/G/H and 569J***D/E (WITHOUT HGBP)
Check Table 8 for maximum suction tube size for 569J units
at minimum load conditions. Consider suction speed riser
(reduced tube size for vertical segment only) or double
suction riser arrangement if the planned suction tube size
does not provide necessary minimum flowrates for this riser.
Table 8 –
569J Maximum Suction Pipe Size
Model: Unit Size
569J***A/B 07
08
12
14
569J*07G/H 07
569J***D/E 12
14
569J*12F 12
569J*12F UNIT WITH OPTIONAL HOT GAS BYPASS
Special consideration for suction riser requirements must
be considered when applying this factory- - installed hot gas
bypass. It is extremely important to consider the lowest
possible refrigerant tons of refrigerant flow when hot gas
bypass is functioning to assure proper oil return up suction
risers.
Table 7 provides recommended tube sizes for model
569J*12F unit which includes the factory- - installed hot
gas bypass system on Circuit 1. The selections in this
table are based on evaluations of system minimum load
operating conditions for comfort cooling applications,
with compressor saturated suction pressure to 28_F
(- - 2.2_C) minimum.
Table 7 includes liquid line size selections based on use of
RTPF coil option only.
Table 7 includes three different suction line size selections
for Circuit 1 based on the elevation difference conditions
between the 569J unit and the evaporator coil location.
Outdoor unit ABOVE evaporator coil: This installation
will have at least one suction riser segment. If the vertical
elevation difference is less than 20- - ft (6.1 m) linear feet
and requires only one or two segments, consider a speed
riser selection for Circuit 1; use the line marked VAPOR
RISER REQUIRED; NOT GREATER THAN 20 FT
(6.1 M). See Fig. 5. Tube S is the horizontal line size;
tube A is the reduced diameter riser size.
Maximum Tube Size
3
1 /
8
5
1 /
8
5
1 /
8
1
2 /
8
1
1 /
8
3
1 /
8
5
1 /
8
See Table 7
A
20-FT (6.1 M) MAX
S
LEGEND
A - Suction Riser Without Trap
S - Suction Line to Condensing Unit
Fig. 5 - - Suction Line Piping - - Speed Riser
If the vertical elevation difference is greater than 20- - ft
(6.1- - m) linear feet or requires more than two short lift
segments, select the Circuit 1 suction line size from
Double Suction Riser lines data under VAPOR RISER
GREATER THAN 20 FT (6.1 M). See Fig. 6. Tube S is
the horizontal line size. Tube A is the reduced diameter
riser size without bottom trap; Tube B is the parallel riser
size with bottom oil trap.
S
FROM
EVAPORATOR
A - Suction Riser Without Trap
B - Suction Riser With Trap
S - Suction Line to Condensing Unit
Fig. 6 - - Suction Line Piping - - Double Riser
Outdoor unit BELOW evaporator coil and no vertical
riser segments: Select Circuit 1 suction line size from
NO VAPOR RISER line.
Circuit 2 suction line: Because there is no hot gas bypass
system in Circuit 2, no special riser selections are
necessary. Select Circuit 2 suction line from bottom line
for all 569J*12F installations.
Vertical Separation (outdoor unit above indoor unit) –
Vertical elevation difference of 200 ft (60 m) is permitted
when the outdoor
569J***D/E/F) is located above the indoor unit.
15
CONDENSING
UNIT
C12404
A
S
B
LEGEND
C12405
unit (569J***A/B/G/H or