Why do they both trip???

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The 100 serves a sprinker booster pump (hp?) that cycles on
against head pressure

the 70 feeds a xfmr and who knows what loads

the fact that ALL 3 are tripping tells me the 70 AND 100 are set too low and taking the main with it

IF they are tripping on inst/oc (vs toc, does it even have a toc element?) turning them up should eliminate switching transients and improve coordination
now
600
300
200
adjust
1600
800
500
the % diff stays the same for trip ratios but the mag is much larger
200 to 100 is 800 vs 300
200 to 70 is 1100 vs 400

obviously he should megger the conductors
damp witing trips toc more often than inst/oc
 
iwire said:
:?




:D

Already done by your truly and a testing company we hired.

Passed both times.
Click to expand...


First post
'fire alarm booster panel'
I've dealt with alot of fa systems and the only time the term 'booster' was used was in relation to a sprinkler system pressure booster/maintaining pump
not a networked zone/annunciation panel
 
Ingenieur said:
First post
'fire alarm booster panel'
I've dealt with alot of fa systems and the only time the term 'booster' was used was in relation to a sprinkler system pressure booster/maintaining pump
not a networked zone/annunciation panel
Click to expand...

Well I work with a lot of fire alarm as well and have never heard of a 'booster panel' in relation to a sprinkler system.

I guess we both learned something today. :)

https://www.google.com/search?q=fire+alarm+booster+panel&ie=utf-8&oe=utf-8
 
imo wrong cb type
should have used a std i/t with an instant region >800% and toc protection

nthing special about the loads to required a adj instant trip only cb
 
OK so I read most of this thread. We have the exact situation for one of our clients. The breaker will trip when going from generator back to utility. It will be a series coordinated fault, tripping breakers straight down the line (3) 225A breakers. There's a transformer at the end at 75kva. We adjusted the instantaneous setting and the problem went away. We felt the problem was due to asymmetrical fault inrush current because it would depend on where in the sine wave it was switched over. This site is also customer owned including transformers upstream.
 
310 BLAZE IT said:
OK so I read most of this thread. We have the exact situation for one of our clients. The breaker will trip when going from generator back to utility. It will be a series coordinated fault, tripping breakers straight down the line (3) 225A breakers. There's a transformer at the end at 75kva. We adjusted the instantaneous setting and the problem went away. We felt the problem was due to asymmetrical fault inrush current because it would depend on where in the sine wave it was switched over. This site is also customer owned including transformers upstream.
Click to expand...
There is no fault, just a temporary spike in current when that transition is made.
 
VFD's wont start a motor already spinning unless they have "on the fly starting" abilities and is enabled, for similar reasons.
 
iwire said:
Right booster pump, jockey pump, pressure maintenance pump likely other names as well but not 'fire alarm booster panel'.
Click to expand...

booster pumps have a fire alarm control panel with pressure controls, starter, alarming, etc.
hence 'fire alarm booster panel'
I do not see 'fire alarm booster panel' on your pnl schedules, only 'fire alarm control panel' and 'fa power suply'

regardless
imo the breakers are set too low and are of the wrong type, no toc element (is that even code compliant for this application?)
perhaps fire alarm, elevator and emergency ltg may be exempt if desired from oc protection? (only need sc)

swap them out for I/t and your problems will disappear and you will have better protection (I think you can leave the main, just crank it up to 800%/1600 A)
 
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Ingenieur said:
imo the breakers are set too low and are of the wrong type, no toc element
Click to expand...

Apparently you have not bothered to look up the actual breaker data sheets yourself.
Magnetic trip only breakers are relatively rare. Magnetic only mounted into standard panelboard construction are extremely rare, and may no longer even exist.
 
Ingenieur said:
booster pumps have a fire alarm control panel with pressure controls, starter, alarming, etc.
hence 'fire alarm booster panel'
I do not see 'fire alarm booster panel' on your pnl schedules, only 'fire alarm control panel' and 'fa power suply'

regardless
imo the breakers are set too low and are of the wrong type, no toc element (is that even code compliant for this application?)
perhaps fire alarm, elevator and emergency ltg may be exempt if desired from oc protection? (only need sc)

swap them out for I/t and your problems will disappear and you will have better protection (I think you can leave the main, just crank it up to 800%/1600 A)
Click to expand...

If you use that term in conversation with anyone who is familiar with both fire alarm and sprinkler, I'm betting 99 out of a hundred will assume you mean a notification appliance booster power supply. especially since it says "alarm", and the hundredth will ask you to repeat the question.
 
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