Ansul system wiring with contactors exhaust keeps on everything else shut off

Status
Not open for further replies.
I can, but you need to answer some questions first:

1. Is there an Ansul-type control box or panel?
2. What is each blower fan motor type?
3. One or two fan switches, and light switch?
4. Gas, electric, or both appliance types?
5. If gas, mechanical or electric valve and reset box?
6. Temperature probe in duct and timer module?
7. Horn/strobe or connect to fire alarm system?
8. Any of this existing or is it an all new installation?

Some answers might trigger more questions.


Also, typical rules state that exhaust must turn on or stay on, make-up air must turn off or stay off, all gas and/or electrical equipment, including receptacles and lights must shut down. Let us know if anything varies from this in your area.
 
As Larry points out there are a lot of things that may or may not be included, in some newer installs this is all taken care of in a package unit.

Roger
 
Thank you for respond.
2 hp 20 amp 220 only 1 fan
No fresh air
Fryer 20 amp 120
Grill also 20 amp 120
Ansul micro switch
Lights
Its new installation
I am thinking to make 1 switch for light only
I did use 2 contactor I am able to connect it with ansul.
In case of fire Recepticle and lights turn off.
Somehow I can't leave the exhaust on.
Exhaust also go off.
 
I made this and posted it here years ago, and it has made its way around the interwebs. Look it over, and I'll tell you how to modify it for your system in a little while.

1582765864933.png
 
Okay, since you have no make-up air, you can use just one microswitch (m/s) for everything. You'll want a 2-pole contactor for the exhaust fan, and you can use a one 2-pole or two 1-pole contactors for the two 120v circuits as well.

Look at the lower diagram. C = common, N = normal, E = emergency. Instead of a horn/strobe, you would have the exhaust fan contactor. One wire to your manual exhaust switch would connect to the incoming power and the C terminal, and the other wire would connect to the E terminal, which connects to the exhaust fan contactor.

So, the m/s tripping removes power from the appliance contactor(s) and the light switch, and energizes the exhaust fan contactor if it's not already on. As I said above, you can have one 2p or two 1p appliance contactors, depending on where you choose to break each appliance circuit. So, as I said, one microswitch will do everything.
 
He also said:

"Somehow I can't leave the exhaust on.
Exhaust also go off."

What does that mean?? Never saw a requirement to shut down the exhaust fan during a fire.

-Hal
 
He was complaining that it wasn't doing what it's supposed to do.

That's why the first thing I plan when wiring a system is to bypass the exhaust fan switch.
 
LarryFine said:
What the mechanical guys call "gravity fed". There are fresh-air grills in the hood, just no blower. Vacuum draws the air in.
Click to expand...
Correct.

Bottom line is there is nothing to turn on/shut off, unless AHJ would require an automatic damper. Still going to draw air through every available opening in the building if the exhaust fan is running. This makes it difficult to break the seal when trying to open a door if it creates enough vacuum., but once seal is broken the door isn't as difficult to continue to open, or can even cause back draft in a natural draft vented appliance - like an old furnace or water heater - still find water heaters of that type.
 
Status
Not open for further replies.
Top