Midco DS45B - Manual (Page 7)

4. IMPORTANT: Make sure that the capacity range of the installed spud and the
preliminary primary air shutter setting are suitable for capacity rating of the gas utilization
equipment. Refer to Section VII and Table 3.
5. RESET the Electronic Control by setting the operating control to OFF or the thermostat
below room temperature for at least 30 seconds. See Section XII .
6. Confirm that Main Manual Shut-Off Valve is open. Turn Manual Gas Cock Knob on
Combination Valve to ON.
7. Turn operating control to ON or set thermostat above room temperature. Main flame
should come on when the motor reaches operating speed. Whenever the burner fails to
light during the 6-second ignition trial, or if the flame is lost during the burner run and is
not re-established within 6 seconds, the Electronic Control will shut off the Combination
Valve and LOCK OUT To RESET the Electronic Control for restart, de-energize the
Electronic Control by setting the operating control to OFF or thermostat below room
temperature for at least 30 seconds. If burner still fails to light, turn it off and repeat from
step 5 above. Then, if necessary, refer to the TROUBLE CHART to isolate the problem.
WARNING: Repeated unsuccessful attempts to light will result in accumulated
gases in gas utilization equipment and chimney. To prevent these gases from
reaching an explosive level, periodically purge the gas utilization equipment
and chimney as described in step 3 above.
8. To make a preliminary setting of the burner input, determine the manifold gas pressure
required from Table 3 and adjust the combination valve main gas pressure regulator
accordingly. See Section XI .
9. To determine the firing rate for NATURAL gas, accurately time test dial for the number of
seconds for one revolution and use the following formula. All other gas utilization
equipment must be off.
Then Divide by 1,000 for MBH value.
For PROPANE gas, consult your supplier for method of determining firing rate
10. Readjust the primary air shutter to provide a quiet, soft blue flame with well defined
orange and yellow tips for NATURAL gas or with well defined yellow tips for PROPANE
gas.
11. Check the operation of the burner; start and stop it several times with the thermostat or
operating control.
12. With the burner running, check the operation of all limit and associated controls.
13. PERFORM THE FOLLOWING FINAL ADJUSTMENTS for combustion and flue gas
temperature. Take the flue gas samples and temperature immediately ahead of the
draft control.
A.
The flue gas temperature should be above 325°F but not exceeding 550°F.
Excessive flue gas temperatures will result in low efficiencies. Low flue gas
temperature may cause excessive condensation. Reset gas input if necessary to
adjust stack temperature.
B. Make the final setting of the primary air shutter by checking the flue gases with an
ORSAT or similar combustion testing instrument. The carbon monoxide content
should conform to local codes, or, in their absence to the level specified in the
United States or Canadian Standard referenced on the front cover of this manual;
and the carbon dioxide content should be approximately 9.5% for NATURAL and
12.1% for PROPANE, or within the limits prescribed by local codes.
14. Check the draft control to make sure there is no spillage of flue products into the room.
15. FILL OUT THE INSTALLATION ADJUSTMENT DATA TAG and affix to the burner or
gas utilization equipment.
NOTE: For subsequent normal starting and shut off procedure, refer to CONSUMER
INSTRUCTIONS or to the instruction plate mounted on the burner.
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7
Part 1 Installation
Part 1
Installation
Continued
VIII Initial Start Up/
Adjustment
3600 x test dial size x BTU value
No. of seconds for one rev. test dial.
= BTU/Hr.
3600 x 1 x 1000
20
= 180,000 BTU/Hr. = 180 MBH Example: