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Topic: Talk to me about compressors (Read 2312 times) previous topic - next topic

Re: Talk to me about compressors

Reply #15 –
https://www.google.com/url?sa=i&url=https%3A%2F%2Fwww.abacaircompressors.com%2Fen%2Fprofessional%2Fmobile%2Fstandard%2Fmobile-air-compressors-11l-11l&psig=AOvVaw2-QhmaWbhdnOLZOIFQ2ZWA&ust=1619291440213000&source=images&cd=vfe&ved=0CAIQjRxqFwoTCPDRkumIlfACFQAAAAAdAAAAABAF
Hi, i have this abac compressor, its a 22 litre twin tank, very portable. I bought it used/non runner with the pressure switch missing. Its a great compressor.
 My neighbor has a wolf one similar to the SGS one you linked, even thugh they are a similar design, they simply dont compare ! The wolf one doesnt have the cfm, it fills slower and you really get what youre paying for ! I use mine every day, nut busting with impact wrenches, inflating tyres and die grinding cylinder heads- it hasnt skipped a beat. I will change the oil this weekend as its overdue ...
 bottom line  is i would rather buy 2nd hand than new cheap, chinese, the windings are alluminium which dont last and the fittings are cheaper- for a reason !

Re: Talk to me about compressors

Reply #16 –
I know you're sorted now but; Bambi. Every. Time.
British made, medical quality, the budget silent range are genuinely super quiet (<40dB) and capable of breathing air quality even on the oil lubricated ones, used by majority of dentists etc across the land.
They do bigger stuff for heavy tools, they are simple, reliable and spares are readily available and they don't change the designs that often.
Got mine off eBay, changed the oil, new seal kit for the motor box and rubber feet that had perished and it literally purrs in the corner of the workshop. It's actually a pleasurable noise..
Also available in vertical configuration for space saving.
For example:
https://www.ebay.co.uk/itm/184861340440?hash=item2b0a983318:g:88cAAOSwbm5gsSUS
https://www.ebay.co.uk/itm/133772378817?hash=item1f257482c1:g:VnIAAOSwU9RgqjV-
The 150/500 is a £1275 unit.

Chris.

Re: Talk to me about compressors

Reply #17 –
Well as an update on this, the new compressor is ace  :)) I keep it pressurised now so it's there ready to use all the time. However on first boot is does often trip the electrics. As part of recent home improvements the garage fusebox was updated. Not sure if the electrician downgraded the spec or if the new breakers are just more sensitive.

This was a warning for the belt drive ones and (apart from being a bit cheaper) the main reason I went for this one so really disappointed this one does that and isn't documented anywhere. There is a spare slot in the fuse board so I might see if I can get a dedicated 40 amp socket put in (Not tried my welder yet but I'm expecting that's going to be problematic too  >:(  )

This was a minor issue, since the garage also holds a freezer of frozen raw dog food, that was allowed to defrost. Luckily it wasn't full. But I now know to keep an eye on it.

Re: Talk to me about compressors

Reply #18 –
What's the MCB rating (incl. the letter)?
I guess it will be a B (i.e. B32). Change it for a C with the same FLC rating. Will allow much higher inrush current from an inductive load (5-10 times, type B is 3-5 times).
You don't need a higher FLC rating if the thing will run with that rating once started, just a different curve.

Re: Talk to me about compressors

Reply #19 –
The Garage is split into 2 parts, a single garage at the front and thanks to a small extension many many years ago (before we moved in) a small workshop on the back of the garage. We moved in 11 years ago and had to have the whole place rewired its a 1960s build. The garage has its own RCB which is fed from the main house one with a super chunky wire. At the time I believe this RCB was considered OK for a garage so whilst the main house RCB was upgraded along with all the wiring, that wasn't changed just new wire, lights and sockets throughout the garage and workshop area.

Last year we had the workshop part of the garage converted to a utility (I was compensated for my loss of workshop with a MASSIVE shed).

I was told the RCB needed to be upgraded now, for domestic use.... or just because ?


The Utility part has B32, but the garage part is now only B16 with another B16 feed off to the shed (outbuilding) this currently ends in a junction box on the outside wall, I haven't run to the shed yet.


Unfortunately I don't know the spec of what was there and didn't have this compressor with that set up, but my old (half the size) compressor worked no issue. I suspect the sockets in the garage are OK for 32 Amp system and swapping the breaker to B32 would be OK, I could run an extension from the Utility, but I haven't tried that yet.

Or maybe if what you've said above for a B32 to C32 would work maybe I just need a C16 ?

tbf, I don't really know and I chatted to a mate (who's a plumber - but has trained to be electrician, just never bothered to go qualified) who said if I burn the house down the insurance might be invalid as my and even then, if we sell by certificates for the work done wouldn't be valid.  Happy to take any advice on this though as you seen to know what you're talking about.

Re: Talk to me about compressors

Reply #20 –
You can only swap to 32 if it's a ring main. Max on single 2.5 T&E is about 26 amps so radial (daisy chain) circuits are always fused lower, you would have to follow the cables to the sockets to see what you have but I would suspect radial if it's fused at 16A.
Yeah C16 would allow more inrush startup current. Motors can pull up to 6x their full load current (normal 'loaded' running current) on startup. B MCBs are intended for mainly resistive (non inductive) domestic loads, any motor is or can be inductive (washing machine etc) but they are specifically designed for domestic applications. An industrial (non domestic) motor design doesn't care about inrush or inductance loading.
In theory if you change anything in your electrical system you are taking responsibility for it, e.g. the last guy who tested and certified it is off the hook if it goes wrong but swapping a B16 for a C16 can cause no real issues. It's just a different trip curve. You can get a D type for transformers and large machinery with huge inrush/startup currents. Also K and Z for specialist shizz:


So your compressor (or anything else) on a B16 or a C16 protected circuit will still trip the MCB if it draws more than 16A eventually. If you get a short to earth the current is going to go huge (multiple times the FLC) and either will trip instantaneously. C will let it draw up to 80A but only for 1 second then it'll trip.

Chris.

Re: Talk to me about compressors

Reply #22 –
Hi chaps, just a Q on the air compressor and tools. I've got a 50l SGS 9.6CFM (the £150 jobby not the £300 14.1CFM jobby I probably should have bought) and some tools like the rotary tool and air saw are pretty pathetic when in use. The rotary tool with a wire wheel stops easily and spins no faster (or not even as fast) as it would in a drill.

What are you guys experiencing on your machine - i think some of you are running the more beefy version of the compressor (14.1CFM) and wondering if it is better for the job.

Cheers
Matt
 

Re: Talk to me about compressors

Reply #23 –
From my research, I think you need to be looking for 12CFM for most tools. I've also seen it recommended that you have an air hose with a minimum internal diameter of 10mm, so the coil hose that comes with most starter kits isn't much cop. I think my old 50l one was 11CFM and just about got away with some tools although for short periods as the tank would drain quite quick.

Without knowing the spec of the tools you have, I had a quick look on SGS at their cut off saw. It says it only requires 4.5CFM but does need an air hose of 3/8" ID (9.5mm).




In other news, I had the electrician back and he replaced the breaker a C rated one, after he went I saw he'd put it in the wrong slot so my compressor still trips the garage electrics - doh!