Table of Contents
Advertisement
A
S
From
Evaporator
LEGEND
A - Suction Riser Without Trap
B - Suction Riser With Trap
S - Suction Line to Condensing Unit
Fig. 5 — Suction Line Piping - Double Riser
Step 5 — Complete Refrigerant Piping
Connections
IMPORTANT: DO NOT BURY REFRIGERANT LINES.
IMPORTANT: A refrigerant receiver is not provided with
the unit. Do not install a receiver.
PROVIDE SAFETY RELIEF
If local codes dictate an additional safety relief device, pur-
chase locally and install locally. Installation will require the
recovery of the factory shipping charge before the factory
tubing can be cut and the supplemental relief device is
installed.
Model CAS123/153 has two separate refrigeration systems.
If required, each circuit will require a field-supplied/installed
supplemental relief device.
CHECK CAS MODEL WITH EVAPORATOR COIL
CONNECTIONS
Confirm before installation of unit that the evaporator coil
connections are consistent with this CAS model. See
Table 3 on page 3.
INSULATE SUCTION LINES
Apply closed-cell tubular insulation to all suction lines be-
tween evaporator coil connection and CAS unit's suction
service valve.
CAS123/153 PIPING CONNECTIONS
The CAS123/153 unit's two circuits are designated Circuit 1
and Circuit 2. Circuit 1 is controlled by the thermostat's Y1
and Y3 contact and will be the first circuit on and last circuit
off. Circuit 2 is controlled by the thermostat's Y2 (or TC2)
contact and this circuit is always the "lag" circuit.
See Fig. 6 for location of Circuit 1 and Circuit 2 service
valves and field piping connections. Circuit 1 is on the right-
hand side of the service valve compartment; Circuit 2 is on
the left.
When a single piece evaporator coil with two separate cir-
cuits is connected to a CAS123/153, the lower coil circuit
should be connected to the CAS123/153 unit's Circuit 1 so
that the evaporator's lower coil segment is first-on/last-off
(to avoid re-evaporation of condensate on dry lower coil
segments).
10
S
B
Plan the Circuit 1 and Circuit 2 tubing segments carefully,
mark each segment and check constantly as piping sys-
tems are assembled to avoid piping errors.
The CAS123/153 unit cannot be field-piped as a single-
circuit/tandem system.
FINAL TUBING CHECK — CAS123/153
Before completing the field piping connections to the
CAS123/153 unit service valves, confirm that the suction
line to the indoor coil's first-on/last-off circuit (and its com-
panion liquid line) are correctly identified as Circuit 1 use
for the CAS123/153 unit. If a suction riser is required, it
must be in Circuit 1.
Connecting F*S/H to CAS123/153
The F*X (6 to 10 tons) and the F*S/H (12.5 tons) fan coils
are a face-split coil design that also has its circuits designat-
ed as 1 and 2. See Table 11 and Fig. 7. Note that the lower
coil segment changes as the arrangement of the F*X/F*S/H
changes. In a vertical arrangement, the F*S/H unit's lower
coil segment is segment 2; this segment should be connect-
ed to the CAS123/153 unit's Circuit 1. In a horizontal ar-
rangement, the F*X/F*S/H unit's lower segment is now seg-
ment 1; this segment should be connected to the
CAS123/153 unit's Circuit 1.
Note that refrigerant suction piping should be insulated.
F*X / F*S/H
ARRANGEMENT
Horizontal
INSTALL FILTER DRIER(S) AND MOISTURE
INDICATOR(S)
Every unit MUST have a filter drier in the liquid line.
CAS123/153 models require two filter driers (one in each
liquid line). Locate the filter drier(s) at the indoor unit, close
to the evaporator coil's thermal expansion valve (TXV)
inlets.
The CAS units include one (CAS072/091/121/151) or two
(CAS123/153) R-410A-duty filter drier(s), shipped in cartons
attached to the unit basepan (see Table 12). Remove the fil-
ter drier(s) and prepare to install in the liquid line(s) at the
evaporator coil. Do not remove connection fitting plugs until
ready to connect and braze the filter drier into the liquid line
position.
Specifications subject to change without notice.
CKT
1
CKT
2
Fig. 6 — CAS123/153 Service Valve Locations
Table 11 — F*X / F*S/H Arrangement Details
COOLING
STAGE
Y1, Y2, and Y3
Vertical
Y2 and Y3
Y2 and Y3
Y1, Y2, and Y3
Circuit 2
Connections
Circuit 1
Connections
F*X / F*S/H
CONNECT TO
COIL
CAS123/153
SEGMENT
2
Circuit 1
1
Circuit 2
1
Circuit 1
2
Circuit 2
CAS-072-153-01SI Rev. A
Advertisement
Table of Contents
