• We will be performing upgrades on the forums and server over the weekend. The forums may be unavailable multiple times for up to an hour each. Thank you for your patience and understanding as we work to make the forums even better.

Pump room controls

Learn the NEC with Mike Holt now!
Status
Not open for further replies.
B

B.VanOsdol

Member
Location
Indianapolis, IN
Occupation
Electrician / Fire Alarm
I have a pump room with a Diesel engine that when starting up needs to turn on a 3P480v,1.3FLA exhaust fan located on the roof and activate a Louver with a solenoid voltage range of 24...240vAC/24...125vDC 9.5vA.

recommendations on how I should accomplish this would be much appreciated.
 
Jraef

Jraef

Moderator, OTD
Staff member
Location
San Francisco Bay Area, CA, USA
Occupation
Electrical Engineer
ptonsparky said:
IDK about the fire pump details, They would be different.

I would be inclined to have it set up that if the louver is not open, the diesel will not start.
Louver opens, turns fan Motor On, allows diesel to run.
Click to expand...
Amen to that. I've seen where the fan starts first and if all of the doors are closed, it pulls a vacuum and the louver motor can't move the louvers. Open lovers, turn on fan, then allow the engine to start.

Do you have 480V in the room for the fan? If not, start there. You would get a Combination Starter for the fan, one that has "extra capacity" on the Control Power Transformer. Then tap off of that CPT for power your louver motor. Wire it so that the Start command to the engine (whatever that is) first closes an Off Delay Time Delay Relay (TDR) . Use the timed contacts of the TDR to energize the louver operator, then run power for the starter coil through the limit switch of the louver to turn on the fan after the louver is open. Then use an aux contact on the fan starter in series withy an instantaneous contact of the TDR to engage the Engine Start relay for the Diesel. The sequence ends up like this:
Engine start call => TDR coil
TDR Timed Contact => louver motor, opens louver
Louver limit switch => Starter coil, turns on fan
Starter Aux + TDR Instant contact => Engine Start Relay

Then when the engine is called for to stop, the TDR instataneous contact drops out the Engine Start Relay and kills the engine. The TDR timed contact stays closed and keeps the fan running for a few minutes (in case there are any exhaust gasses). Then when the timer times out, it kills power to the fan starter coil to shut off the fan, as well as power to the louver. This assumes that the louver will close by itself when power is removed. If the louver operator must be powered to close, it gets a little more complex.
 
J

JRW 70

Senior Member
Location
Eastern Central Missouri
Occupation
Testing and Engineer
Is there a generator for the building? If the electric happens to go off then will the louver close on its own? For a fire pump, the fan/louver situation will need to be addressed so it works in all conditions. If there’s a source for a circuit that is backed up by a generator, that would be the better choice for the fan etc.
 
tom baker

tom baker

First Chief Moderator & NEC Expert
Staff member
Location
Bremerton, Washington
Occupation
Master Electrician
NFPA 20 goes hand in hand with Article 695. I had a fire pump station with one electric 1500 GPM and one diesel 1500 GPM pump.
The DFP had a small control panel for the exhaust fan and intake louvers, HOA, wth the auto from an aux contact in the DFP controller. The louvers had an actuator to drive and maintain shut, but were spring open in case of a power failure to provide combustion air to the DFP.
Again, make sure you have a copy of NFPA 20, ask your fire or building dept AHJ what edition to use. NFPA 20 has a lot of requirements that are not in the NEC. Just remember fire pumps are painted red, and that makes everything more expensive
 
B

B.VanOsdol

Member
Location
Indianapolis, IN
Occupation
Electrician / Fire Alarm
Thank you all for the input. Many things I had not considered were pointed out to me here and I will be sure to take them all into consideration
 
G

george54

Member
Location
Chicago
Occupation
electrician
Have you determined this is a fire pump? A fire pump cannot be cutoff if a louver doesn't open.

The diesel controller will have an auxillary contact (pump running signal) that you can use. Usually they are unpowered contacts. The newer controllers can be programmed for additional contacts.
 
StarCat

StarCat

Industrial Engineering Tech
Location
Moab, UT USA
Occupation
Imdustrial Engineering Technician - HVACR Electrical and Mechanical Systems
This is very similar to an Evap cooler relief damper arrangement I have installed. I am using a relay and a current sensing relay on the fan to open the damper set.
The CT relay powers an octal base relay to open the damper. Very easy to do.
 
G

george54

Member
Location
Chicago
Occupation
electrician
B.VanOsdol said:
I have a pump room with a Diesel engine that when starting up needs to turn on a 3P480v,1.3FLA exhaust fan located on the roof and activate a Louver with a solenoid voltage range of 24...240vAC/24...125vDC 9.5vA.

recommendations on how I should accomplish this would be much appreciated.
Click to expand...

This is the correct method:

Find a pump run signal or aux contact to energize the coil of a relay with two Normally open contacts. When the pump runs, the relay is energized and the relay contacts will operate the louver and exhaust fan. Attached is a schematic. Other manufacturers have similar external terminations.
 

Attachments

  • Metron HCFD5F Field Connections Website.pdf
    96.4 KB · Views: 26
tom baker

tom baker

First Chief Moderator & NEC Expert
Staff member
Location
Bremerton, Washington
Occupation
Master Electrician
Shouldn't the louver be spring open and held normally closed with an actuator? The DFP will start if power is lost, don't want to depend on power to open the louver.
 
StarCat

StarCat

Industrial Engineering Tech
Location
Moab, UT USA
Occupation
Imdustrial Engineering Technician - HVACR Electrical and Mechanical Systems
The best failsafe for any given control system is worth considering of course. I have found its often difficult to come up with best scenario when under fire and time constraints. Especially with relay logic.
 
Dibloafer911

Dibloafer911

You shall not pass
Location
Palm Coast, FL
Occupation
Controls, estimating, engineering
tom baker said:
Shouldn't the louver be spring open and held normally closed with an actuator? The DFP will start if power is lost, don't want to depend on power to open the louver.
Click to expand...
I'd be inclined to install it with this logic. Spring-return fail safe actuator. Louver is held shut through NC contacts of pilot relay with 24v. Initial switch opens louver by dropping out power to actuator through relay. Same pilot relay can also energize NO contactor to EF. Engine start/stop relay interlocks with EF/actuator relay. Logic: Engine cannot start unless actuator is open with fan on
 
G

george54

Member
Location
Chicago
Occupation
electrician
The OP mentions a diesel engine in a pump room. In all the years I have worked on controls for pumps, louvers and fans are never a reason to lockout a pump. Fire pumps run until pressure is satisfied or the building burns down and/or the electric / diesel supply is no longer adequate. Fire pumps do not have any safety lockouts. Electric fire pumps do not have overload blocks.
 
Status
Not open for further replies.
Top