Input Rate Adjustment Specifications - Slant/Fin CB-45 Installation And Operating Instructions Manual

The input rate for the Concept boiler, on Direct Vent or
Category IV installations, may be set up to a maximum of
15% above to 25% below the nominal specified rating plate
input of each model. See Chart 1. This allowance is useful in
better sizing the boiler's input rate to each installation site's
heat load.
The input rate for the Concept boiler, on Category I
installations, must only be set to one specified input rate for
each model. See Chart 2. This rate, which is typically higher
than the nominal specified rating plate input for each model
(except the CB-180), will ensure that a high enough flue
temperature is obtained to safeguard against condensation
forming in the flue piping and chimney stack. On all Category
I installations, the air pressure switch provided on the boiler
must be replaced with the switch provided in vent kit 665194.
This switch is set to prevent the boiler from operating below
the approved Category I input rate.
Chart 1:
Input Rate Adjustment Specifications for Direct Vent and Category IV Installations
CB-45
w BTUH
9 890 33,750
10 550 36,000
11 210 38,250
11 870 40,500
12 530 42,750
13 190 45,000
13 850 47,250
14 510 49,500
15 170 51,750
* Follow instruction manual operation procedures, Step C, to set with meter. Ability to attain input rates over the nominal rating plate specifications
may be constrained by installation variables such as vent length, altitude, and calorific value of the gas, particularly on the larger models of boilers.
† Follow instruction manual operation procedures, Step A, to set with gauge.
Chart 2:
This chart must be used for Input Rate Adjustment for Category I Installations
Boiler Category I Input Rate *
Model
w
CB-45 16 120
CB-90 30 480
CB-135 42 500
CB-180 52 760
* Follow instruction manual operation procedures, Step C, to set with meter.
† Follow instruction manual operation procedures, Step A, to set with gauge.
Provisions for combustion and ventilation air must be made in accordance with Section 5.3, air for combustion and ventilation, CSA 149.1-00 for
natural gas and propane..
20

Input Rate Adjustment Specifications

Boiler Model and Allowable Input *
CB-90
w BTUH w
19 780 67,500 29 670
21 100 72,000 31 650
22 420 76,500 33 630
23 740 81,000 35 610
25 060 85,500 37 590
26 380 90,000 39 570
27 700 94,500 41 550
29 020 99,000 43 530
30 340 103,500 45 510
Differential Pressure †
BTUH mm w.c.
55,000 25.40
104,000 21.59
145,000 19.05
180,000 16.51
To set the input rate of the Concept boiler perform the
following adjustment procedure:
A. Refer to the Operation Procedures on pages 18 and 19
which specify the methods of calibrating the boiler'
components for proper input rate and air/gas ratio.
B. Note that Step A and Step C are followed to set rate only
depending on whether a differential pressure gauge or a
gas meter is available. Either method is adequate to se
input, or both can be performed as a verification of inpu
rate. Use these procedures, in conjunction with the
appropriate chart below, to adjust the input rate a
specified for that venting application.
C. Note that Step B is followed to set the air/gas ratio only
not to set input rate. Follow Step B precisely as specified
in the instruction manual.
CB-135 CB-180
BTUH w
101,250 39 560
108,000 42 200
114,750 44 840
121,500 47 480
128,250 50 120
135,000 52 760
141,750 55 400
148,500 58 040
155,250 60 680
Air Flow Percent of increase
over nominal boiler
input rate
in. w.c.
1.00
.85
.75
.65
Air Flow
Differential
Pressure †
BTUH mm w.c. in.w.c.
135,000 10.67 .42
144,000 12.19 .48
153,000 13.72 .54
162,000 15.49 .61
171,000 17.27 .68
180,000 19.05 .75
189,000 21.08 .83
198,000 23.11 .91
207,000 25.15 .99
22%
15%
7%
0%
Percent of change
to nominal boiler
input rate
Reduced by 25%
Reduced by 20%
Reduced by 15%
Reduced by 10%
Reduced by 5%
Nominal 0%
Increased by 5%
Increased by 10%
Increased by 15%