88-4YCA4001-1A-EN
15
2. Clock the gas meter with the furnace operating
(determine the dial rating of the meter) for one
revolution.
3. Match the “Sec” column in the Gas Flow (in cfh)
with the time clocked.
4. Read the “Flow” column opposite the number of
seconds clocked.
5.
lists values for a 2 cubic foot dial. For
1, 1/2, or 5 Cu. Ft. dials use the following
conversions:
•
1 Cu. Ft. Dial Gas Flow CFH = Chart Flow
Reading / 2
•
1/2 Cu Ft. Dial Gas Flow CFH = Chart Flow
Reading / 4
•
5 Cu. Ft. Dial Gas Flow CFH = 10X Chart Flow
Reading / 4
6. Multiply the final figure by the heating value of the
gas obtained from the utility company and compare
to the nameplate rating. This must not exceed the
nameplate rating.
7. Changes can be made by adjusting the manifold
pressure.
a. Attach a manifold pressure gauge to the Outlet
Pressure Tap.
b. Remove the cover screw on top of the gas valve
to access the manifold pressure adjustment
screw.
c. Turn the adjustment screw in to increase the
gas flow rate, and out to decrease the gas flow
rate using a 3/32" hex wrench or flat-head
screwdriver.
N
No
otte
e:: For manifold pressures and orifice sizes for gas
with other BTU ratings, contact the local gas
utility. Manifold pressure should be 3.5 inches
water column (+ 0.1). Input for natural gas must
n
no
ott exceed the value shown on the rating plate.
Figure 10.
Burner and Valve
Regulator Cover Screw
(Adj. screw beneath
this screw)
Manual
On-Off
Switch
Inlet
Pressure
Tap
Vent Post
Outlet
Pressure Tap
REF. VIEW
(GAS VALVE)
Orifice
Burner
Manifold
Gas Valve
REF. VIEW
(3 Burners)
Table 7. Gas Flow (in cfh)
Sec.
Flow
Sec.
Flow
Sec.
Flow
Sec.
Flow
8
900
29
248
50
144
82
88
9
800
30
240
51
141
84
86
10
720
31
232
52
138
86
84
11
655
32
225
53
136
88
82
12
600
33
218
54
133
90
80
13
555
34
212
55
131
92
78
14
514
35
206
56
129
94
76
15
480
36
200
57
126
96
75
16
450
37
195
58
124
98
73
17
424
38
189
59
122
100
72
Table 7. Gas Flow (in cfh) (continued)
Sec.
Flow
Sec.
Flow
Sec.
Flow
Sec.
Flow
18
400
39
185
60
120
104
69
19
379
40
180
62
116
108
67
20
360
41
176
64
112
112
64
21
343
42
172
66
109
116
62
22
327
43
167
68
106
120
60
23
313
44
164
70
103
124
58
24
300
45
160
72
100
128
56
25
288
46
157
74
97
132
54
26
277
47
153
76
95
136
53