Bauer K17 min speed?

[broncobowsher]

I have a manual for a K17 compressor. Lists a lot of stuff. But what I need to know is what the minimum compressor speed is. That one spec is not in the manual. I can't find it online either.

Once I know that I will know what needs to be done to make this compressor that is sitting around usable.

 

[michael-fisch]

Since the K17 has an oil pump, it shouldn't suffer from being run too slow. Normal speeds are between 800 and 1150rpm, but since it has an oil pump being run at 600rpm shouldn't cause a problem.

Michael

 

[broncobowsher]

Thank you. That helps a lot. Next step for me is to figure the original compressor speed with the 15HP motor and try to see how well it can scale back with a 10HP motor. I've heard the K17 will run fine on 10HP. Not ideal, but it is all I am allowed.

 

[tbone1004]

Since the K17 has an oil pump, it shouldn't suffer from being run too slow. Normal speeds are between 800 and 1150rpm, but since it has an oil pump being run at 600rpm shouldn't cause a problem.

Michael

is the last stage not splash lubricated? I thought it had one splash stage

@broncobowsher electric I assume? It will be somewhat variable speed with either motor as it will start to slow down at the high pressure range when it starts needing more power. If filling lots of big/high pressure banks, you'll probably want to cycle it a bit by filling one at a time vs. opening the full bank for filling. I wouldn't think 10hp will be slow enough for the RPM range on it though.

 

[broncobowsher]

Correct, electric. We have been struggling with this for over a year. No 3-phase on the property, not economical to bring in. Can't change property. Stuck with single phase, no options. Single to 3-phase convertors exist, but you are fighting losses at each conversion. The building is old, don't have enough capacity to draw another 5HP on top of the 10 the building already has. I sometimes even cringe at the 10HP load that is on it now, but it pulls it fine. There is this good used K17 with a 480V 3-phase motor everyone wants to use. Someone talked with someone at Bauer and was told it will run fine on 10HP. But they didn't ask the right questions (shaft RPM at 10HP?). I don't know the connection or else I would talk to them myself. It gets tough working on stuff for other people when there are middle men in the middle. Left in the dark, trying to fill in the blanks.

 

[tbone1004]

@broncobowsher what electrical supply does the building have, and what motor is on there now? Specific question to the motor is whether it is dual voltage as many of the 480v will also have wiring options for 240v....
Can you get a picture of the motor dataplate? If it can be rewired for 240v, then you are going to be able to get it set up for about $600 on the existing motor :-D

 

[broncobowsher]

Building is single phase ONLY. I will have to look at what breaker is in there now, it is pushing the panel to the limit now. The quote to bring 3-phase in was over 5 figures, not going to happen.

Motor:
Marathon UVH 215TTDR7001EPL
Frame: 215T
Type: TDR
DES: B
Phase :3
Code G
Insulation class B
Enclosure: Drip proof
Duty: Continous
Max temp 40°C
Amp 40-37.4/18.7
Volt 208-230/460
RPM 3490
HZ 60
HP15
Service Factor 1.15
NEMA Nom EFF: 86.5
Nom PF: 86.1
Max Cap KVAR: 5.8
Corr amp: 35.5-33/16.5
{Unlabeled line} H107

 

[tbone1004]

@broncobowsher you got lucky, no reason to change the motor.

What is the breaker capacity that this will be plugged into? Fingers crossed at least a 30a breaker....

You are going to have to rewire the motor and put a smaller pulley on it to slow the pump down, then buy a VFD.
I'd get this one. We use them in our plant for other stuff though not as 3p converters since we have a substation in the backyard and have 600v service :-D
GS4-2025 | AC High-performance Drive: 230 VAC, 25hp with 3-phase input, 10hp with 1-phase input, (VFD) (PN# GS4-2025) | AutomationDirect

my air compressors are 500hp, they're beasts

 

[BRT]

@broncobowsher you got lucky, no reason to change the motor.

What is the breaker capacity that this will be plugged into? Fingers crossed at least a 30a breaker....

You are going to have to rewire the motor and put a smaller pulley on it to slow the pump down, then buy a VFD.
I'd get this one. We use them in our plant for other stuff though not as 3p converters since we have a substation in the backyard and have 600v service :-D
GS4-2025 | AC High-performance Drive: 230 VAC, 25hp with 3-phase input, 10hp with 1-phase input, (VFD) (PN# GS4-2025) | AutomationDirect

my air compressors are 500hp, they're beasts

I think that plan is shaky. I have probably installed (and operated) 50-100 vfd's and I would not try to operate a motor that has a higher HP rating than the drive. I do like to oversize drives for the motor. I understand that you are going to pull less hp by slowing it down...but.
A viable plan may be to run it on a phase converter which will give 2/3 output hp and slow it down.

 

[tbone1004]

@BRT when I spec drives at the plant I oversize them as well, but you are limited when using it as a phase converter because they are severely downrated by the manufacturer for heat. You have to go up to a 60hp drive to get 15hp single phase. The one I linked is a 25hp drive and even the 50hp drive in that series is only rated for 10hp1p. The 60hp is way overkill IMO for that, certainly at 3x the cost.
He's trying to run 10hp, so running 2/3 the RPM will give him that with the same pulleys. It's not really ideal, but it is what it is when using the VFD's.

I'm sure there are some other 15hp1p vfd's out there if you go digging, that's just a decent series to find. General rule of thumb if using a generic VFD for single phase is to double the hp rating. Technically only have to go 1.73 (sqrt3) which in this case is 25hp, and you'll be fine since the amp draw is the same. I don't know why those are derated as far as they are. If concerned, just go to double the HP rating and you'll be fine.

Problem with a normal phase converter is you still need to add the soft starts in there and the costs get crazy.