Importance of ESP, Gas Pressure, and Voltage for Gas-Fired Units

1
Importance of ESP, Gas Pressure, and Voltage for
Gas-Fired Units

• Presented by
• Bruce Standerwick

2
Importance of ESP, Gas Pressure, and Voltage for
Gas-Fired Units

• Part 1
• The Importance of ESP on Gas-Fired Units

3
Two Cases When Actual ESP not Equal to Design ESP

• Case A Actual ESP gt Design ESP
• Case B Actual ESP lt Design ESP

4
Design Point
2.1
TSP W.C.
4,100 cfm
CFM in 1000s
5
Actual Operation Case A
2.6
2.1
TSP W.C.
4,100 cfm
3,780 cfm
CFM in 1000s
6
Case A Actual ESP gt Design ESP

• Solutions
• Adjust sheave if possible
• Change sheave and possibly belts

7
Actual Operation Case A
3.0 BHP
2.6
2.1
2.6 BHP
TSP W.C.
4,100 cfm
3,780 cfm
CFM in 1000s
8
Case A Actual ESP gtDesign ESP

• Solutions
• Adjust sheave if possible
• Change sheave and possibly belts
• Need (1), (2) and possibly larger motor size with
  new motor controls -- Will motor fit?

9
Motor Compartment of DFC
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Case A Actual ESP gt Design ESP

• Solutions
• Adjust sheave if possible
• Change sheave and possibly belts
• Need (1), (2) and possibly larger motor size with
  new motor controls -- Will motor fit?
• Shaft deflection may require larger shaft and
  bearings

11
Fan Assembly Under Construction
12
Motor Compartment of DFC
13
Operating Point
New Operating Point
Design Point
TSP W.C.
3,900 cfm
CFM in 1000s
14
Fan Assembly Under Construction
This dimension is smaller on a fan with a narrow
housing
15
Case A Actual ESP gt Design ESP

• Solutions
• Need sheave change
• Need (1) and larger motor and controls
• Need (1), (2) and possibly larger motor size with
  new motor controls -- Will motor fit?
• Shaft deflection may require larger shaft and
  bearings
• Different fan because new cfm/TSP point is not in
  operating range of fan in unit

16
Actual Operation Case B
2.1
1.6
TSP W.C.
4,550 cfm
CFM in 1000s
4,100 cfm
17
Case B Actual ESP lt Design ESP

• Solutions
• Adjust sheave if possible
• Change sheave and possibly belts

18
When Actual ESP is Different From Design ESP

• Conclusions
• Its easier to slow a fan down than to speed it
  up
• Its safer to overestimate the ESP than to
  underestimate it!

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Importance of ESP, Gas Pressure, and Voltage for
Gas-Fired Units

• Part 2
• The Importance of Gas Pressure for Gas-Fired Units

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Typical Gas-Fired Pipe Train in Piping Compartment
21
Typical Direct Gas-Fired Pipe Train
Main Gas Pressure Regulator
Main Gas Valve
Auxiliary Gas Valve
Maxitrol Modulating Gas Valve
Gas manifold start of factory furnished and
piped components
Pilot
Main Gas Shutoff Valve
Test Port
Test Port
Test Port
Pilot Gas Shutoff Valve
Pilot Gas Pressure Regulator
Pilot Gas Valve
Orificed Needle Valve
22
Direct Gas-Fired Burner in Burner Compartment
23
Direct Gas-Fired Burner at Full Fire
24
Typical Direct Gas-Fired Heater RatingPlate
Max. Gas Inlet Pressure
Min. Gas Inlet Pressure
25
Two Cases Where Actual Gas Pressure not Equal to
Design Gas Pressure

• Case A Actual Gas Pressure gt Design Gas pressure
• Case B Actual Gas Pressure lt Design Gas pressure

26
Case A Actual Gas Pressure gt Design Gas Pressure
Main Gas Pressure Regulator
Main Gas Valve
Auxiliary Gas Valve
Maxitrol Modulating Gas Valve
¾ I.P.S. gas manifold 5 psig actual gas
pressure instead of 10-14 w.c. per design
Pilot
Main Gas Shutoff Valve
Test Port
Test Port
Test Port
Pilot Gas Shutoff Valve
Pilot Gas Pressure Regulator
Pilot Gas Valve
Orificed Needle Valve
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Solution for Case AActual Gas Pressure gt Design
Gas Pressure

• Install a High Gas Pressure Regulator

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Case B Actual Gas Pressure lt Design Gas Pressure
Main Gas Pressure Regulator
Main Gas Valve
Auxiliary Gas Valve
Maxitrol Modulating Gas Valve
2 I.P.S. manifold 10 w.c. gas pressure instead
of 1-2 psig per design
Pilot
Main Gas Shutoff Valve
Test Port
Test Port
Test Port
Pilot Gas Shutoff Valve
Pilot Gas Pressure Regulator
Pilot Gas Valve
Orificed Needle Valve
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Case B Actual Gas Pressure lt Design Gas Pressure

• Solutions
• Add section to burner
• Modify sheet metal in burner section

30
When Actual Gas Pressure is Different From Design
Gas Pressure

• Conclusions
• Its much easier in the field to add a high gas
  pressure regulator than to rebuild a gas
  train/burner
• Its safer to underestimate the gas pressure than
  to overestimate it!

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Importance of ESP, Gas Pressure, and Voltage for
Gas-Fired Units

• Part 3
• The Importance of Voltage on Gas-Fired Units

32
Motor Compartment of DFC
33
Components That Could be Affected by a Voltage
Change

• Disconnect Switch and/or Distribution Block
• Fuses and Fuse Blocks
• Circuit Breaker
• Transformers
• Starter and Overload Contactors
• Motor(s)
• Wiring and conduit to motor(s)
• Wiring diagram

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Relationship Between Volts and Amps

• HP is proportional to volts times amps
• If HP1 HP2 then
• (volts x amps)1 (volts x amps)2 or
• (volts1/volts2) (amps2/amps1)
• Amps are inversely proportional to volts at
  constant horsepower.

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Two Cases Where Actual Voltage not Equal to
Design Voltage

• Case A Actual Voltage gt Design Voltage
• Case B Actual Voltage lt Design Voltage

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Case A Actual Voltage gt Design Voltage
Disconnect Switch and/or Distribution Blocks No change
Fuses and Fuse Blocks Fuses probably change fuse blocks also if different fuse type required
Circuit Breaker Probably need to change so it will trip when necessary.
Transformers Must change unless original transformer is tri-voltage (208/230/460).
Starters No change
Overload Contactors Probably need to change so it will trip when necessary.
Motor(s) Must change unless original motor is tri-voltage (208/230/460).
Wiring and Conduit No change
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Case B Actual Voltage lt Design Voltage
Disconnect Switch and/or Distribution Blocks Non-fused disconnect may change fused disconnect will change
Fuses and Fuse Blocks Fuses probably change fuse blocks also if different fuse type required
Circuit Breaker Doesnt change because its downstream of transformer
Transformers Must change unless original transformer is tri-voltage (208/230/460)
Starters Must change
Overload Contactors Must change
Motor(s) Must change unless original transformer is tri-voltage (208/230/460).
Wiring and Conduit May change depending on original amp rating
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When Actual Voltage is Different From Design
Voltage

• Conclusions
• Fewer components are likely to need changing if
  the voltage goes up (amps go down) rather than if
  the voltage going down (amps go up)
• Its safer to underestimate the voltage than to
  overestimate it!
• Wiring diagram, specification sheet and rating
  plate must be replaced if the voltage changes

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Importance of ESP, Gas Pressure, and Voltage for
Gas-Fired Units

• The End
• Thank You!