Refrigerant Line Connection; Coil Cleaning; Air System Adjustment; Air Flow Data - Static Pressure Drop - York MC SEries Installation Manual

841890-UIM-B-0612
SECTION VII: REFRIGERANT LINE
CONNECTION
Coil is under inert gas pressure. Relieve pressure from coil by
removing rubber plug or by depressing schrader core.
Dry nitrogen should always be supplied through the tubing while it
is being brazed, because the temperature required is high enough
to cause oxidation of the copper unless an inert atmosphere is pro-
vided. The flow of dry nitrogen should continue until the joint has
cooled. Always use a pressure regulator and safety valve to insure
that only low pressure dry nitrogen is introduced into the tubing.
Only a small flow is necessary to displace air and prevent oxidation.
Connect lines as follows:
NOTICE
Route the refrigerant lines to the coil in a manner that will not
obstruct service access to the coil, air handling system, furnace flue
or filter.
1. Suction and liquid line connections are made outside the cabinet.
Leave the tubing connection panel attached to the cabinet with the
tubes protruding through it. Coil access panel should be removed
for brazing. The lines are expanded to receive the field line set
tubes.
2. Cut the end of the suction tube using a tube cutter. Place the tube
cutter as close as possible to the end of the tube to allow more
space for the connection and brazing of the suction line.
3. Remove the heat shield from the Customer Packet, soak in water,
and install over coil tubing to prevent overheating of cabinet.
4. Wrap a water soaked rag around the coil connection tubes inside
the cabinet to avoid damaging the TXV bulb.
5. Remove grommets where tubes exit the cabinet to prevent burning
them during brazing.
6. Purge refrigerant lines with dry nitrogen.
7. Braze the suction and liquid lines.
8. Remove the heat shield.
9. Re-attach the grommets to the lines carefully to prevent air leak-
age.
10. Attach the coil access panel to the cabinet.
Refer to Outdoor unit Installation Manual for evacuation, leak check and
charging instructions.
Lines should be sound isolated by using appropriate hangers or strap-
ping.
All evaporator coil connections are copper-to-copper and should be
brazed with a phosphorous-copper alloy material such as Silfos-5 or
equivalent. DO NOT use soft solder.
8
SECTION VIII: COIL CLEANING
If the coil needs to be cleaned, it should be washed with Calgon Cal-
Clean (mix one part CalClean to seven parts water). Allow solution to
remain on coil for 30 minutes before rinsing with clean water. Solution
should not be permitted to come in contact with painted surfaces.
SECTION IX: AIR SYSTEM ADJUSTMENT
To check the CFM, measure the static pressure drop across the coil
using a portable manometer and static pressure tips. To prepare coil for
static pressure drop measurements - the system should have been
recently operational in cooling mode.
NOTICE
Table 7 below has WET coil data. Run system for approximately 15
minutes in cooling mode prior to taking measurements.
Drill 2 holes, one 3" after the coil (before any elbows in the ductwork)
and one 3" before the coil. Insert the pressure tips and read the pres-
sure drop from the manometer. See Table 5 to determine the air flow,
and make the necessary adjustments to keep the CFM within the air
flow limitations of the coil.
TABLE 6: Air Flow Data - Static Pressure Drop
CFM @ Static Pressure Drop - IWG
Coil Size
0.10
18A 400
18B 425
24A 400
24B 425
30A 425
30B 450
32A 555
35B 600
35C 792 1007
36A 625
37A 689
36B 825
36C 975 1225
42B 825 1000
42C 1025 1275
43C 785 1025
48C 900 1075
48D 1008 1224
60D 1160 1432
62D 1240 1532
64D 1152 1362
(Based on wet coil)
0.15 0.20 0.25
550 710 880
620 830 970
600 800 950
725 900 1075
600 800 950
725 900 1075
725 865 970
800 950 1090
1206 1382
775 925 1025
880 1031 1180
976 1174 1300
1375 1575
1175 1325
1475 1650
1210 1400
1300 1475
1451 1620
1598 1750
1709 1870
1573 1783
0.30
1000
1125
1075
1215
1075
1215
1080
1220
1572
1125
1300
1450
1775
1450
1850
1570
1600
1788
1870
2000
1994