Unico 3642 User Manual

Bulletin 30-20 — Page 25
© Copyright 2010, Unico, Inc.
used. The phase-out schedule is timed so that R-22 is
available for expected lifespan of the R-22 equipment.
The Unico System is completely compatible with R-
410A. Using R-410A with the Unico System is a simple
matter of changing the expansion valve. The refrigerant
coil is shipped with an R-22 expansion valve that must
be changed to an R-410A expansion valve for the correct
tonnage needed.
Maintenance
When service is required to the motor or the wheel, the
entire assembly may be removed as a unit (see figure
28). The blower assembly unit is accessible from the
piping connection side of the unit. It is not necessary to
access both sides of the unit. Nor is it necessary to dis-
connect any module or ducting.
To remove the motor and blower wheel assembly, loosen
the six (6) screws fastening the motorized blower as-
sembly to the blower housing. Twist the motorized
blower assembly counter-clockwise (CCW) and pull the
assembly away from the blower housing.
CAUTION
TO PREVENT DAMAGE TO THE
WHEEL BALANCE, DO NOT GRAB
THE ASSEMBLY BY THE WHEEL OR
SET THE ASSEMBLY DOWN SUCH
THAT THE WHEEL IS SUPPORTING
THE ASSEMBLY. ALWAYS SET THE
ASSEMBLY DOWN WITH THE WHEEL
ON TOP.
Once the assembly is removed, the proper service may
be preformed. If the wheel is to be changed, it may simp-
ly be removed from the motor shaft by loosening the
motor set screw and pulling the blower wheel off the
motor shaft. If the motor is to be changed, first the blow-
er wheel must be removed as mentioned above, and then
the screws fastening the motor to the inlet ring must be
removed.
To re-install the motorized blower assembly back into
the blower housing, follow the steps mentioned above in
reverse order.
Figure 28. Removal of the Motorized Blower Assembly
Table 8a. R-22 / 410A Satura-
tion Pressure – Temperature
(English units)
°F
psig
R-22 R-410A
0
24.0 48.4
2 25.7 51.1
4
27.4 53.8
6
29.2 56.6
8 31.0 59.4
10
32.8 62.4
12
34.8 65.4
14 36.8 68.6
16
38.8 71.8
18 40.9 75.1
20
43.1 78.5
22
45.3 82.1
24 47.6 85.7
26
50.0 89.4
28
52.4 93.2
30 55.0 97.2
32
57.5 101.
34
60.2 105.
36 62.9 110.
38
65.7 114.
40 68.6 119.
42
71.5 123.
44
74.5 128.
46 77.6 133.
48
80.8 138.
50
84.1 143.
55 92.6 156.
60
102. 170.
.
.
.
.
.
.
.
.
.
90
168. 274.
95
182. 295.
100 196. 317.
105
211. 341.
110
226. 365.
115 243. 391.
120
260. 418.
125 278. 447.
130
297. 477.
Table 8b. R-22 / 410A Satu-
ration Pressure – Tempera-
ture (SI units)
°C
kPa (gauge)
R-22 R-410A
-18
163 330
-17
174. 347
-16
184 363
-15
195 380
-14
206 398
-13
217 416
-12
229 434
-11
241 453
-10
253 473
-9
266 493
-8
279 513
-7
293 534
-6
306 556
-5
320 578
-4
335 601
-3
350 624
-2
365 648
-1
381 673
0
397 698
1
413 723
2
430 750
3
447 777
4
465 804
5
483 833
6
501 861
7
520 891
8
540 922
9
559 953
10
580 984
12
622 1050
14
665 1120
.
.
.
.
.
.
.
.
.
30
1090 1780
32
1150 1880
34
1220 1980
36
1290 2090
38
1360 2200
40
1430 2320
42
1510 2440
44
1590 2560
46
1670 2690
48
1750 2820
50
1840 2960
52
1930 3100
54
2030 3250

Unico 3642 Specifications

General

Brand	Unico
Model	3642
Category	Air Handlers
Language	English