4
Table 2 – Refrigerant Connections and Recommended Liquid
and Vapor Tube Diameters (In.)
UNIT SIZE
LIQUID
RATED VAPOR
Connection
Diameter
Tube
Diameter
Connection
Diameter
Tube
Diameter
18, 24
3/8
3/8
5/8
5/8
30, 36
3/8
3/8
3/4
3/4
42, 48
3/8
3/8
7/8
7/8
60
3/8
3/8
7/8
1–1/8
* Units are rated with 25 ft. (7.6 m) of lineset. See Product Data sheet for performance
data when using different size and length linesets.
Notes
:
1. Do not apply capillary tube indoor coils to these units.
2. For Tubing Set lengths between 80 and 200 ft. (24.38 and 60.96 m) horizontal or
20 ft. (6.09 m) vertical differential 250 ft. (76.2 m) Total Equivalent Length, refer to
the Residential Piping and Longline Guideline – Air Conditioners and Heat Pumps
using Puron refrigerant.
Installing with Indoor Piston
Outdoor Unit Connected to Factory Approved Indoor Unit
Check piston size shipped with indoor unit to see if it matches
required indoor piston size. If it does not match, replace indoor
piston with correct piston size.
NOTE
: Correct pistons are shipped with outdoor units in the
accessory bag and are only qualified for piston fan coils. Example
fan coils with piston: FB4C and FY5B (1.5 through 4 ton)
When changing indoor piston, use a back
−
up wrench. Hand
tighten hex nut, then tighten with wrench 1/2 turn. Do not exceed
30 ft
−
lbs. The indoor piston contains a Teflon ring (or seal) which
is used to seat against the inside of distributor body, and must be
installed properly to ensure proper seating. See Fig. 5.
13/16” BRASS HEX NUT
TEFLON
®
SEAL
TEFLON
®
RINGS
3/4” BRASS HEX BODY
“H” DISTRIBUTOR
PISTON RETAINER
PISTON
A10342
Fig. 5 -- Indoor Piston Installation
Install Liquid Line Filter Drier Indoor
Refer to Fig. 6 and install filter drier as follows:
1. Braze 5 in. (127 mm) liquid tube to the indoor coil.
2. Wrap filter drier with damp cloth.
3. Braze filter drier to 5 in. (127 mm) long liquid tube from
step 1.
4. Connect and braze liquid refrigerant tube to the filter drier.
A05227
Fig. 6 -- Liquid Line Filter Drier
CAUTION
!
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment damage
or improper operation.
Installation of filter drier in liquid line is required.
Evacuate Refrigerant Tubing and Indoor Coil
CAUTION
!
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment
damage or improper operation.
Never use the system compressor as a vacuum pump.
Refrigerant tubes and indoor coil should be evacuated using the
recommended deep vacuum method of 500 microns. The alternate
triple evacuation method may be used (see triple evacuation
procedure in service manual). Always break a vacuum with dry
nitrogen.
Deep Vacuum Method
The deep vacuum method requires a vacuum pump capable of
pulling a vacuum of 500 microns and a vacuum gage capable of
accurately measuring this vacuum depth. The deep vacuum method
is the most positive way of assuring a system is free of air and
liquid water. A tight dry system will hold a vacuum of 1000
microns after approximately 7 minutes. (See Fig. 7.)
500
MINUTES
0
1
2
3
4
5
6
7
1000
1500
LEAK IN
SYSTEM
VACUUM TIGHT
TOO WET
TIGHT
DRY SYSTEM
2000
M
ICRO
NS
2500
3000
3500
4000
4500
5000
A95424
A95424
Fig. 7 -- Deep Vacuum Graph
Final Tubing Check
IMPORTANT
: Check to be certain factory tubing on both indoor
and outdoor unit has not shifted during shipment. Ensure tubes are
not rubbing against each other or any sheet metal. Pay close
attention to feeder tubes, makings sure wire ties on feeder tubes are
secure and tight.
Be sure field wiring complies with local and national fire, safety,
and electrical codes, and voltage to system is within limits shown
on unit rating plate. Contact local power company for correction of
improper voltage. See unit rating plate for recommended circuit
protection device.
NOTE
: Operation of unit on improper line voltage constitutes
abuse and could affect unit reliability. See unit rating plate. Do not
install unit in system where voltage may fluctuate above or below
permissible limits.
25H
B
B
/25H
B
C
/25H
C
D
