AERCO BMK 1500-2000 - Manual (Page 50)

Benchmark 1500 - 2000 Boilers
CHAPTER 3 – OPERATION
Page 50 of 188 AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 OMM-0097_0D
Ph.: 800-526-0288
GF-142
3.11 START/STOP LEVELS
The start and stop levels are the Air/Fuel Valve positions (% open) that start and stop the unit,
based on load. These levels are Factory preset as follows:
BMK 1500 BMK 2000
Start Level: 24% 24%
Stop Level: 16% 16%
Normally, these settings should not require adjustment.
Note that the energy input of the boiler is not linearly related to the Air/Fuel Valve position. Refer
to Table 3-8 for the relationship between the energy input and Air/Fuel Valve position for a BMK
1500 MBH boiler running on natural gas.
Table 3-8a:
BMK 1500:
Relationship Between Air/Fuel Valve Position and
Energy Input Running On Natural Gas
Air/Fuel Valve
Position
(% Open)
Energy Input
(BTU/Hr)
Boiler Energy Input
(% of Full Capacity)
16% (Stop Level) 76,000 5.0%
20% 127,000 8.5%
30% 366,000 24.4%
40% 629,000 41.9%
50% 822,000 54.7%
60% 977,000 65.0%
70% 1,119,000 74.5%
80% 1,255,000 83.5%
90% 1,396,000 92.9%
100% 1,502,000 100%
Table 3-8b:
BMK 2000:
Relationship Between Air/Fuel Valve Position and
Energy Input Running On Natural Gas
Air/Fuel Valve
Position
(% Open)
Energy Input
(BTU/Hr)
Boiler Energy Input
(% of Full Capacity)
16% (Stop Level) 100,000 6.7%
20% 143,000 11%
30% 388,000 23%
40% 759,000 37%
50% 1,069,000 51%
60% 1,283,000 61%
70% 1,476,000 74%
80% 1,675,000 83%
90% 1,833,000 93%
100% 2,000,000 100%