AERCO BMK 2000DF - Manual (Page 52)

Benchmark 1500DF - 2000DF Boilers
CHAPTER 3 – OPERATION
Page 52 of 196 AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 OMM-0098_0A
04/01/2014 Ph.: 800-526-0288 GF-144
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 and should not require adjustment:
Natural Gas Propane Gas
BMK 1500 BMK 2000 BMK 1500 BMK 2000
Start Level: 24% 24% 24% 24%
Stop Level: 16% 16% 18% 16%
Note that the energy input of the boiler is not linearly related to the Air/Fuel Valve position. Refer
to Table 3-8a and 3-8b 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
Natural Gas Propane Gas
Air/Fuel Valve
Position
(% Open)
Energy Input
(BTU/Hr)
Boiler Energy
Input (% of Full
Capacity)
Energy Input
(BTU/Hr)
Boiler Energy
Input (% of Full
Capacity)
16% (Stop Level) 75,000 5.0% 18% 75,000 5.0%
20% 107,000 7.1% 93,700 6.2%
30% 281,000 18.7% 254,000 16.9%
40% 536,000 35.7% 505,000 33.7%
50% 717,000 47.8% 680,000 45.3%
60% 848,000 56.5% 807,000 53.8%
70% 992,000 66.1% 947,000 63.1%
80% 1,184,000 78.9% 1,157,000 77.1%
90% 1,393,000 92.9% 1,379,000 91.9%
100% 1,507,000 100% 1,503,000 100%
Table 3-8b:
BMK 2000:
Relationship Between Air/Fuel Valve Position and
Energy Input Running
Natural Gas Propane Gas
Air/Fuel Valve
Position
(% Open)
Energy Input
(BTU/Hr)
Boiler Energy
Input (% of
Full Capacity)
Energy Input
(BTU/Hr)
Boiler Energy
Input (% of Full
Capacity)
16% (Stop Level) 100,000 5.0% 100,000 5.0%
20% 132,000 6.6% 126,600 6.3%
30% 410,000 20.5% 363,000 18.2%
40% 786,000 39.3% 677,000 33.9%
50% 1,045,000 52.3% 898,000 44.9%
60% 1,280,000 64.0% 1,070,000 53.5%
70% 1,546,000 77.3% 1,242,000 62.1%
80% 1,686,000 84.3% 1,523,000 76.2%
90% 1,866,000 93.3% 1,845,000 92.3%
100% 2,000,000 100% 2,000,000 100%