looking for electric compressor for my boat

[veriqster]

if you are looking for a 3 phase converter have a look at RONK, i'm yet to hear anything bad about them. not sure how suitable they would be for a boat, they are not solid state so are "quite" heavy.
also, try contacting them if you have any questions, i've dealt with them and though the unit i got was a second hand i was impressed with the quality of they customer service and their expertise; wish there would be more companies like this.
my understanding is that their unit alleviate starting current issues, i run the inverter through a 30 amp breaker. i'll look up the exact specs on the motor but i believe it's around 2.5 kw.

 

[frogman62]

Handy,
I have several compressors on boats and 10-15 purchased by Scubaboard members. Units are 19X19X34 inch frame, 3 hp 4.2 cfm at up to 4500psi. Grade E or better air and very long life military compressors (new surplus Kidde's). I also have a repair policy that no one can compete with. IF your compressor goes out in normal operation (except you failed to keep oil in the unit) You send me the compressor only and I'll repair it for $250 or less and have it back in shipping in 48 hours or less.
Look me up with other members and at < sheldensportinggoods.com >
Jim Shelden
316-992-0505

 

[bentetzner]

Hi,
I happen to have a small Bauer 2 cfm with gas motor. Am contemplating selling because I will probably have to give up diving.
Ben

 

[frogman62]

Handy,
I now have 3 each, 6 CFM Noah-Howden Compressors that I am completely going through for new valves and seals (since I have many factory/depot overhaul kits). I can build one up for you with a 5 HP 220vt, 3 phase motor ( that will pump all day if need be). If the filter system is located where you can manually drain the moisture trap at 30 minute intervals (no auto drain). The unit will sell for $3900 plus shipping and provide grade E at a fill rate of 6 CFM -- Fill your 80's in 14 minutes from 0-3000PSI.
Jim Shelden
316-992-0505
sheldensportinggoods.com

 

[bentetzner]

Hi,
I have a small Bauer for sale. Has a gas motor, though. Very reliable and well maintained unit. I can be reached at 510 278-7169. Can't figure out how to post pictures, but they can be seen on craigslist.:depressed:
Ben

 

[svbravo]

With single phase, 220, 60Hz, here is the straight-up starting requirements, with no load.

2hp-6.5Kw
3hp-8Kw


Craig

Craig
I currently have a Northern Lights 5kw diesel genset on our 46' sailboat. Would like to install an electric compressor, and power it w/ this existing genset. Is there any way to use a "soft start" unit of some type to allow successful operation of a small compressor w/ 5kw? I don't want to use a gas compressor for a number of reasons, including need to carry addl gas on a diesel boat.

Sorry if this has been addressed before.

Thanks
Adam
s/v Bravo

 

[CraigAClark]

I keep hearing people talk about "soft start", but I have never laid eyes on one that will work for single phase. Does your genset have 220v capability? I'm not going to say your Northern Lights will work, but I had a client with a Gulf Stream and same size NL genset that would start a 2 hp Bauer. The unit was a Utilus 10 (called a Purus with a 2 hp motor) which has been discontinued and replaced with the current Junior II. What a shame. BTW, all other power draws had to be turned off when the compressor was started.

You can also check with the motor manufacturer to see if the capacitors can be changed. I've done that before with a Lesson 2 hp motor operating on 60 Hz.

The other solution is a frequency drive. These are generally designed for 3 phase motors, but sometimes, depending on manufacturer, a larger unit can be rated for single phase use. These work by allowing the motor speed to ramp up over an extended time period, keeping the in rush amperage lower over the start up period. I'm no expert in sizing these, but with a 2 hp, it would probably require a drive for a 5 hp on 3 phase. You would have to contact the manufacturer for size info. Most of the ones I used were for 7.5 hp, single phase, 50 Hz, which required a 15 hp 3 phase unit. Just keep in mind that some situations can't be solved with a drive. An example would be a 12.5 Kw genset and 7.5 hp motor.

Craig

 

[svbravo]

Good info, Craig, thanks for the quick response.

I just spoke w/ a marine electrician in Seattle who services the NL gensets, to see if he'd seen any of my units installed w/ a compressor. He said that he saw a compressor that had a Baldor soft start device installed as part of the OEM package, but he couldn't recall the brand of the compressor. Does anyone know which compressor mfr offers the Baldor softstart as an option??? He said it converts the 120V / 1 ph genset output to 240V / 3 ph. Is this the "frequency drive" that you mention, Craig??

He also recommended that I get the genset no load output changed to 63 hz, 125V. Said any competent marine electrician here in Mex should be able to do it.

Has anyone had experience w/ mods of this sort??? Does it pass "the sniff test" for viability, or do folks think I'm chasing my tail trying to make this 5kw genset power a compressor???

Also, has anyone had any FIRST HAND EXPERIENCE in using a system of this type??? Your input would be appreciated mucho!!!

Cheers
Adam
s/v Bravo

 

[CraigAClark]

Sorry, I forgot the most important part with the "frequency drive" (also called an inverter drive), the motor on the compressor is changed to a 3 phase motor or built that way. The drive takes the incoming 220V single phase and "creates" the third leg of the 3 phase.

It could be a frequency drive, but I've never had call to convert 120v single phase to 220v (240v) 3 phase. Not sure if that can actually happen. Most of the drives I used were Baldor, but Toshiba makes a decent drive. You can do some cool things besides just starting with a frequency drive, depending on how it is equipped.

Craig

 

[Zodiacdiverdave]

One more option may be open to you, that is to use an hydraulic motor to drive your compressor. The hydraulic pump comes right off one of the drive engines so you have lots of power there to drive any compressor.

ZDD