04-09-2004, 10:00 PM #1
AMPS generator problems and smoke ejectors
What do you power with your AMPS generators? Has anyone using AMPS generators had a failure attributed to high start-up currents of smoke ejector motors, or other similar loads? We have two 15KW units, and have had three separate failures to date (they are 2 years old). The most recent problem is being blamed on the start-up current requirements of the ejector we use, a Super Vac HF164E, which requires 15.4 amps (per the nameplate), but startup draws are higher. I'm interested in any failure info, and how AMPS handled the problem. Thanks in advance.R.A. Ricciuti
Mt. Lebanon Fire Department
04-10-2004, 06:47 PM #2
We currently have 4 AMPS generators on 3 of our Engines and 1 Ladder. One of the Engines is a retrofit. We have had some problems, mostly the shafts and bearings. Are you starting the generators first and then starting the fans? We have been told that we should not engage the generators with a load on them. Maybe this could be the problem.Stay Safe & Bring 'em Home!
I.A.F.F. Local 3008
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** "The comments made here are this person's views and not that of the organizations to which I am affiliated" **
04-13-2004, 10:17 AM #3
Few things here.
Run amperage on that motor according to the SuperVac website is 16.8 amps at 110V, startup IS going to be substantially higher. Also, some other info direct from the SuperVac website: Minimum circuit size should be 20A and the maximum distance for an extension cord is 100' of 10 gauge wire. The AMPS website indicates that there is 126 amps available on that 15KW generator. Did you exceed any of these parameters?
We had a similar problem starting our Ramfan PPV fans off of a diesel 12.5 KW generator. Generator is capable of handling 104 AMPS. Turns out that our particular fans at 110V were drawing around 74 Amps on startup!! They would settle in at about 35-40 amps running. So when we went to start both fans they would lug the generator or pop a breaker - reason - we were trying to pull 145+ Amps from the generator. Solution? 2 fold, only start one fan at a time (simple right?) and we ended up getting a revised motor/fan design that pulled substatially less Amperage. We have not had any problems since then.
A few other items to consider. There are some fans that have a soft start feature to them, it limits the startup draw on the generator. Also, what else is running when you try to start these fans?
There are alot of parameters that may have caused the generator to fail, my dept. has learned that the hard way.
Hope this helps.
Last edited by TCFD12; 04-13-2004 at 10:38 AM."The hero is commonly the simplest and obscurest of men."
-Henry David Thoreau
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04-13-2004, 10:43 PM #4
- Join Date
- Apr 2004
YOU MIGHT START BY RUNNING AN AMP LOAD REPORT ON YOUR FAN. THE LOCAL ELECTRIC PROVIDER OR COOP SHOULD BR ABLE TO HELP DO THIS. IF NOT FIND AN ELECTRICAL CONTRACTOR WHO HAS THE APPROPRIATE AMP METERS W/ RECORD FUNCTION. MANY TIMES AS ELECTRIC DRIVEN MOTORS AGE THEY ACTUALLY DRAW FAR MORE CURRENT THAN THE WONDERFUL SPEC. TAG WILL HAVE STATED. WE HAVE RUN INTO THIS PROBLEM ON MORE THAN ONE OCCASION HERE AT OUR FARMING OPERATION. AS THE PARTS WEAR AND START WORKING LESS EFFIECENTLY THE AMP PULL CLIMBS. WE HAVE HAD OUR RURAL ELCTRIC COOP PERFORM THIS SAME AMP LOAD TEST SO I KNOW IT WORKS. IT WILL RECORD SPIKE (START UP) AMP LOAD AND RECORD THE NOMINAL WORKING LOAD.
WE HAVE ALSO ZAPPED MORE THAN ONE GENRATOR AT THE FIRE DEPT. I WORK FOR WITH LOOSE CONNECTIONS. THE CORD IS A COMMON PLACE FOR THIS. IT WILL ARC OUT DURING THE HIGH AMP LOAD OF START UP AND CAUSE A VOLTAGE SPIKE WHICH THE RECTIFIERS AND OTHER SENSITIVE PARTS DO NOT LIKE. WE ARE CURRENLTY WAITING ON FIVE NEW TRUCKS W/ HYDRAULIC GEN SETS ON BOARD. THESE WILL BE OUR FIRST SO I CAN'T HELP YOU THERE. GOOD LUCK AND GOD BLESS
04-14-2004, 02:58 PM #5
Not a bad idea. Give it a load test. See what happens. The generator at the apartment high rise where I work gets a load test every year and any problems get fixed. Now I realize there is a slight size difference, but it cant hurt to see if it is functioning properly.
Is there any sort of warranty left? See if the manufacturer will test it.
04-14-2004, 08:59 PM #6
raricciuti, a rule of thumb is that starting current will be about 3 times that of the rated run current. Max run current is also listed and rated only for any factory attached cord. Attaching the fan to a extremely long extension cord will drastically change that. Can you power the fan off an outlet fed by the AMPS with out using your extension cord? If so, try that and see if you are getting the same results. If not, it's the extension cord that is causing a voltage drop that corresponds to a proportional current increase, tripping the system. Much like TCFD outlined.
One way to help prevent this is to stutter start the fan. Momentarily start the fan a few times until it is up to speed, then keep let it run.My posts reflect my views and opinions, not the organization I work for or my IAFF local. Some of which they may not agree. I.A.C.O.J. member
"I ask, Sir, what is the militia? It is the whole people. To disarm the people is the best and most effectual way to enslave them."
Co-author of the Second Amendment
during Virginia's Convention to Ratify the Constitution, 1788
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