LumberJocks

Questions for electrical Pros out there / Or those with Becker Pump experience

  • Advertise with us

« back to Power Tools, Hardware and Accessories forum

Forum topic by Jerry posted 07-13-2014 02:51 AM 868 views 0 times favorited 22 replies Add to Favorites Watch
View Jerry's profile

Jerry

2247 posts in 2297 days


07-13-2014 02:51 AM

Got a CNC and came with a Becker Vac Pump 5.5 KW. The becker pump, I have no experience with, seems to have a unique sound to it that I am not accustomed to. But it just trips my 30 amp 3 phase breaker.

A lot I don’t know, but what I do know as fact:

- Breaker it is running on is a little older, could be a faulty breaker…

- 5.5 KW works out to roughly 7.5 hp, well within capacity of 30 amp 3 phase breaker

- Checking amps under load. At start up I am pulling near 100 amps per wire (or around 300 amps total for all 3 wires). Under running power I am pulling around 32 amps per wire.

- Am I incorrect in thinking that if I am pulling 32 amps per wire on 3 hot wires, that I am actually drawing around 96 amps total running amps for that 30 amp breaker. If that is the case, then it is very well possible that I might have an issue with the Becker pump causing the higher loads.

- When I do kill the power to the Becker pump, it comes to almost an immediate stop, sort of giving me the impression that it is spinning under tension, or could use some lube.

- In my research, I find there are front and back bearings on the pump itself that have grease fittings, possible the bearings just need some lube.

So what does all of the smart folks out there think.

Thanks, Jerry

-- Jerry Nettrour, San Antonio, www.topqualitycabinets.net


22 replies so far

View DIYaholic's profile

DIYaholic

14620 posts in 1425 days


#1 posted 07-13-2014 03:17 PM

Sorry, I’m of no real help here….

Have you posted your question over on www.canzone.com ???
It is a site devoted to ALL things CNC. Someone there should be able to answer your question(s).

Good luck.

-- Randy-- I may not be good...but I am slow! If good things come to those who wait.... Why is procrastination a bad thing?

View Jerry's profile

Jerry

2247 posts in 2297 days


#2 posted 07-13-2014 03:35 PM

Thanks Randy, I might need to try another site like the one you posted. There are a few electricians on this site that I figured could offer some information. But unless I am missing something, I think I sort of answered my own question. It appears I am pulling an estimated 96 amps running since I have 32 amps per wire under load. If that is how it is added up, then the Becker pump is drawing too much current. I suspect there is an issue with the pump. I will be further diagnosing the pump, starting with greasing the bearings and ensuring there are no obstructions in the pump causing friction under use.

Thanks, Jerry

-- Jerry Nettrour, San Antonio, www.topqualitycabinets.net

View TheFridge's profile

TheFridge

1031 posts in 236 days


#3 posted 07-13-2014 04:02 PM

Don’t worry about adding the loads up, if the equip nameplate says 20A, it’s 20 across all legs. I’m assuming you have a 120/208v system since it’s 3 ph.

5500w divided by (208×1.732)= roughly 15.25-16A or thereabouts depending on power factor and efficiency.

Is the motor a 7.5 hp or is it just rated in watts?

-- Shooting down the walls of heartache. Bang bang. I am. The warrior.

View bigblockyeti's profile

bigblockyeti

1812 posts in 471 days


#4 posted 07-13-2014 04:08 PM

Something is definitely wrong with the pump if it’s drawing that kind of current after getting up to speed. I have a Gast and while it does stop fairly quickly when the power is removed (with a load, less so with no load) it still turns freely. I had another Gast before that had a cracked vane that eventually cracked the rotor and while it would still turn, was very difficult to do so. So much that it had the 1/2hp motor stalled. Parts should be available and it can be rebuilt provided the shaft isn’t bent and the inside of the rotor housing isn’t galled.

View TheFridge's profile

TheFridge

1031 posts in 236 days


#5 posted 07-13-2014 10:12 PM

Is it rated in watts? Durp.

-- Shooting down the walls of heartache. Bang bang. I am. The warrior.

View Jerry's profile

Jerry

2247 posts in 2297 days


#6 posted 07-13-2014 10:22 PM

Just says 5.5 kw. Otherwise it is not rated in hp

-- Jerry Nettrour, San Antonio, www.topqualitycabinets.net

View TheFridge's profile

TheFridge

1031 posts in 236 days


#7 posted 07-14-2014 02:06 AM

I realized after my first post you already answered my question. Just a durp moment that’s all.

I’m in agreement with the above poster. Something is in a bind. No way it should draw that much amperage.

-- Shooting down the walls of heartache. Bang bang. I am. The warrior.

View Jerry's profile

Jerry

2247 posts in 2297 days


#8 posted 07-14-2014 02:14 AM

Yeah, I will be looking at the pump this week. Hopefully it is something simple.

I am looking at the raptor 18g nails right now. I dont want to buy a raptor nail gun but I dont see any reason why our senco could not shoot those nails.

-- Jerry Nettrour, San Antonio, www.topqualitycabinets.net

View Jerry's profile

Jerry

2247 posts in 2297 days


#9 posted 07-16-2014 02:51 AM

My schedule has not given me any opportunity to look further into the Becker pump. What I have discovered from speaking to an electrician on a job site is that you don’t add the amps across the 3 wires, meaning I am not drawing 96 amps total, but rather just 32 amps. But calculations for a 5.5 kw motor would indicate I should be drawing around 13-14 amps per wire so I certainly have to look further into the pump deal.

Good news is the CNC, which is the primary machine in this purchase, works excellent and we could not be happier.

For now, I purchased a box of plastic nails (Raptor nails) and will be holding our material down with the Raptor nails. This should work out great for what we will be doing with nesting sheet goods.

I am certain when I have the time to look further into the pump that I will be able to get the pump running very well.

Thanks everyone.

-- Jerry Nettrour, San Antonio, www.topqualitycabinets.net

View TheFridge's profile

TheFridge

1031 posts in 236 days


#10 posted 07-16-2014 03:03 AM

Good luck bud

-- Shooting down the walls of heartache. Bang bang. I am. The warrior.

View TopamaxSurvivor's profile

TopamaxSurvivor

15088 posts in 2426 days


#11 posted 07-17-2014 04:43 AM

Did you check to see if it is wired for the correct voltage?

-- "some old things are lovely, warm still with life ... of the forgotten men who made them." - D.H. Lawrence

View CypressAndPine's profile

CypressAndPine

35 posts in 558 days


#12 posted 07-17-2014 05:08 PM

You are pulling 32amps as far as we are concerned. There is an issue if your 5.5KW pump is pulling that many amps.

Is the motor coupled to the pump?? If so, undo the coupling and you can tell if the pump or motor is hard to turn. (I’m not familiar with the equipment.

Either way, it sound like a bearing is bad. Don’t keep trying to run it or you will burn up the electric motor and then have two issues. Your only issue for now is that the motor is being overloaded. I’ll look up the unit on the internet and maybe come up with more advice.

I’m an industrial electrician and I work on motors all day. Hopefully you can trust me.

-- Cypress Jake, New Orleans

View CypressAndPine's profile

CypressAndPine

35 posts in 558 days


#13 posted 07-17-2014 05:14 PM

Does your pump look like this?

-- Cypress Jake, New Orleans

View TopamaxSurvivor's profile

TopamaxSurvivor

15088 posts in 2426 days


#14 posted 07-17-2014 05:55 PM

Foreign motors are often rated in KW instead of HP. Are you sure it isn’t rated for 380 v and 50 hz?

-- "some old things are lovely, warm still with life ... of the forgotten men who made them." - D.H. Lawrence

View Jerry's profile

Jerry

2247 posts in 2297 days


#15 posted 07-17-2014 06:41 PM

Hey guys, thanks for all of the help. I can use whatever I can get. I have been on a couple job sites all week and have not had shop time so have not looked at the becker pump since last week. I like the idea of separating the motor and pump and trying to isolate the issue to either the pump or the motor. Also I will check to confirm the volts, right now I am running on 220 240v.

I will respond later with answers to the questions. Again, thanks for the assistance.

By the way, I have no temptation to run it until I am sure of what is going on, if there is a problem, no sense in making it worse. I have ordered these plastic 18g nails for manual hold down.

-- Jerry Nettrour, San Antonio, www.topqualitycabinets.net

showing 1 through 15 of 22 replies

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics

HomeRefurbers.com

Latest Projects | Latest Blog Entries | Latest Forum Topics

GardenTenders.com :: gardening showcase