Start-Up Direct Gas
important
For proper unit function and safety, follow the start- up procedure in the exact order that it is presented.
important
This
1. Check the Supply Gas Pressure
Check the supply gas pressure and compare it with the unit’s nameplate pressure requirements. Adjust the supply regulator as needed until the supply gas pressure is within the specified range. The direct gas nameplate is located on the outside of the unit on the control center side.
Minimum and maximum gas pressures for maximum output
3. Set the Burner Air Pressure Differential
With the fan running and discharging 70ºF (21ºC) air, connect a
Outer Sensing Probes
7
0.625 - 0.675 in. wc
6
Manometer
Measuring the Pressure Drop
The proper static pressure should be between 0.625 and 0.675 inches wc (155.68 and 168.64 Pa). If needed, evenly adjust the baffles on both sides of the
MAX BTU/HR
BTU/H MAX
NORMAL MANIFOLD
PRESSURE“ W.C.
PRESSION DÕADMISSION NORMALE
MIN GAS
PRESSURE“ W.C.
PRESSION DE GAZ
MIN BURNER
PRESSURE DROP“ W.C. PERTE MIN DE PRESSION
DANS LE BRULEUR
TYPE OF GAS
NATURE DU GAZ
EQUIPPED FOR | AGAINST |
| SCFM |
CONCU POUR | CONTE |
MIN BTU/HR
BTU/H MIN
MIN GAS PRESSURE
FOR MAX OUTPUT“ W.C. PRESSION DE GAZ MIN
POUR PUISSANCE MAX
MAX GAS
PRESSURE“ W.C.
PRESSION DE GAZ MAX
MAX BURNER
PRESSURE DROPPSI PERTE MAX DE PRESSION
DANS LE BRULEUR
DESIGN ∆T | F | |
∆T NORMALE | ||
| ||
|
| |
| EXTERNAL STATIC PRESSURE | |
“ W.C. |
| |
| PRESSION STATIQUE EXTERIEURE |
burner, keeping the burner centered in the opening until the required pressure is obtained.
|
| Burner | |
Adjustable |
| Adjustable | |
Baffle |
|
| Baffle |
|
|
|
|
Airflow | Airflow |
Type of gas
Direct Gas Nameplate
2. Check the Pilot Gas Pressure
Check the pilot gas pressure. The recommended gas pressure is 3 in. wc. Adjust the pilot regulator as needed. See the Gas Train Layout in the Reference section for the location of the pilot pressure test port and pilot regulator.
important
Proper air velocity over the burner is critical on direct fired gas units. If the air velocity is not within the unit specifications, the unit will not operate efficiently, may have sporadic shutdowns, and may produce excessive carbon monoxide (CO) or other gases.
10Model VSU
Burner and Baffles
note
The pressure drop was set at the factory and may not need adjustment.
note
When required pressure is obtained, be sure to reconnect the outer sensing probes.
important
This process may need to be repeated until the proper pressure is achieved. This adjustment will change the air quantity delivered by the unit and therefore the air quantity delivered should be rechecked. Refer to the Blower
note
To increase the static pressure decrease the opening. To decrease the static pressure increase the opening.
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