240 - 110 - 240 Transformer in RV

[Keith and Debs]

Hi all

Hopefully someone will be able to point me in the right direction here.

Our 240 - 110 stepdown stepup transformer is now 8 years old and the laminations are loose and it is becoming increasingly noisy by the day, so much so that we call it the buzzy box now...

Question is does anyone know where we can get a replacement from (without it costing an arm and a leg) before the neighbours start to complain about sleepless nights.

thanks in advance

Keith..

 

[American Dream]

Hi all

Hopefully someone will be able to point me in the right direction here.

Our 240 - 110 stepdown stepup transformer is now 8 years old and the laminations are loose and it is becoming increasingly noisy by the day, so much so that we call it the buzzy box now...

Question is does anyone know where we can get a replacement from (without it costing an arm and a leg) before the neighbours start to complain about sleepless nights.

thanks in advance

Keith..

Yep.

Just bought One on ebay.Construction site transformer.

Nice bit of kit.

Do a search.works really well and real quiet.


Item number: 160173263281

£39.99 + 10.98 postage.Very heavy but does the job.

Bought 2 110v plugs with it so it connects up nicely.

Worth a look anyway.

 

[Keith and Debs]

Thanks for that but its not really what i am looking for... Construction site transformers are only step down and are not rated for continuous use i.e. 24/7

keith

 

[Digger Driver]

Yep
You can't beat construction transformers

Just a shame i am not working on a new build or i might be able to acquire one for you

 

[olley]

Hi you can only use a construction site tranny in one direction ie. 240-110v you cannot reverse it and get 240 from 110.

Olley

PS beaten by 1 minute

 

[American Dream]

Thanks for that but its not really what i am looking for... Construction site transformers are only step down and are not rated for continuous use i.e. 24/7

keith

No Prob. I read it that you were after a step-down transformer.oh:

 

[Geo]

Click on banner at top of page Stateside Tuning or PM Linda (LC1864)oops slip of the finger LC1962
Geo

 

[Lindy-C]

Click on banner at top of page Stateside Tuning or PM Linda (LC1864)oops slip of the finger LC1962
Geo

Better watch that slippery finger Geo......could land you in all sorts of bother!

 

[Geo]

 

[scotjimland]

Hi you can only use a construction site tranny in one direction ie. 240-110v you cannot reverse it and get 240 from 110.

Olley

PS beaten by 1 minute

Errr sorry to disagree.. mine is a 3 kva construction tranny and it works as a step down and step up .. and it's been in constant use 24/7 for the past 8 months ..

however, if you want the best buy one of these ..

Link Removed

 

[olley]

Hi Jim interesting, as I understand it construction trannys are centre tapped for the earth with two lives of 55volts each 180degrees out of phase, making them very safe in use. Again as I understand it your genny produces 110v with single live and neutral, so I would guess that you may get 240v but at only half the wattage.

Have to say I am treading water here, and I am not a good swimmer.

Olley

PS just found this: here: Link Removed

Transformers are not designed to be run continually at their full capacity. They are designed to run tools intermittently and rest between uses.

Intermittent use is defined as 5 minutes continuous use and 15 minutes of inactivity.

If you have an application that requires a continuous load on the transformer then you need to calculate the load at approximately 60% of the transformers capabilities.

Site lighting and electric heating coils are applications that draw continually and therefore…

Airlink transformers have a continuous load rating included in the specifications for this purpose.

Eg.

Airlink Transformer’s ST3300/2 : 3.3kVA (3300W) portable tool transformer has a continuous VA (W) rating at 2000VA (2kVA)(2000W). Approximately 60% of the intermittent rating.

Site lighting requiring 2000W will draw continuously from your transformer and you will require a transformer that is rated at or above 3300W (3.3kVA).

 

[scotjimland]

Hi Jim interesting, as I understand it construction trannys are centre tapped for the neutral with two lives of 55volts each 180degrees out of phase, making them very safe in use. Again as I understand it your genny produces 110v with single live and neutral, so I would guess that you may get 240v but at only half the wattage.

Have to say I am treading water here, and I am not a good swimmer.

Olley

Hi Ian

to be frank I've never given it much thought, only used the genny a few times and never really in anger, but now you're raised the question I'll investigate and get back with a more constructive reply .. and a life belt ..

 

[olley]

Hi Jim I added a PS from a site I found.

Olley

 

[scotjimland]

Hi Jim I added a PS from a site I found.

Olley

Thanks Ian ..
That would explain why mine is ok running 24/7 , it only has the fridge and the water heater to cope with and they aren't pulling a full load all the time .. Clearly it wouldn't be man enough if we ran both or even one air con unit..

Must think about replacing.... :Sad:

 

[monacosteve]

I have seen a motorhome were they had a construction transformer inside under the bed, they smelt something burning, when they lifted the transformer it had burnt the carpet, i dont know why but be carefull.

steve

 

[American Dream]

Mine was only bought to power the Atwood LPG/110V water heater.

Well within spec and works well.

Use the genny for anything else although mostly 240v.

Wouldn't run an air-con off it though

 

[johnsandywhite]

:Cool: I am using a 3.5 KVA Transformer bought from Machine Mart intended for permanent on-site heating. We do not need 240 volts. That comes from Solar power and an inverter. If necessary? I can plug the charger into the 110volt side to charge the batteries when there isn't enough Solar power produced.

 

[Lampie]

When I got my RV it came with a construction type transformer ie yellow box. Yes they will work 24 / 7 but are not designed to do so. Also when you first plug in on a site the in rush voltage to the transformer is so great for that split second that it is possible and in many cases over loads the trip. It is very annoying trying to explain to site wardens that " no there is not a fault with the van , it's just the transformer starting up ! "

So I changed mine to one that is meant to be run 24/7 and that has a soft start system built in. Never had a trip go since well happy with it. Have a look Link Removed

Regards


Lampie

 

[Forestboy]

So I changed mine to one that is meant to be run 24/7 and that has a soft start system built in. Never had a trip go since well happy with it. Have a look http://www.griffin-american-motorhom.../tripping.html


Hi Lampie
I was thinking about one of the soft start systems as I'm fed up of going to get the electric turned back on, it's always a CC site that it happens on and the wardens always in the middle of his tea. Get the usual "this only ever happens with American M/Hs" comment

I saw an article by Griffin but have been waitng to hear a review about them I take it from your comments it works well.

Was it expensive and how long did it take to fit, I presume it was fitted by Griffin.
Thanks in advance :thumb:

 

[Jim]

I have been told if this happens a way round it is to start the genny and then hook up. Never tried it yet, but would it work?

 

[olley]

Hi Jim if it was wired for the auto changeover switch to select ehu over the jenny then I would imagine so. But most of ours have been converted to 240v so how my relays are now set up I don't know, certainly the ehu is dead when the genny is running, but whether if I was to plug it in it would disconnect the genny or do nothing i don't know.

If its been wired wrong it could stuff 240v straight into the genny, with expensive results. So not something I would try unless by accident.

Olley

 

[johnsandywhite]

:Cool: Hi olley. The Auto-Changeover is set to switch to the genny when it starts and disconnects the shore power.

 

[olley]

Hi John it that case plugging the EHU in would do zilch!

I suppose you could start the genny, then connect the EHU, then turn the genny off and the relay should drop out and connect the EHU. Thats providing the bloke who did the 240v conversion didn't do anything silly when he converted it. oh:

Personally if I had a problem I would spend the money on a soft start tranny, or I believe they can retro fit it to your existing tranny. Mines only ever tripped the site MCB once and keith was on hand with a screwdriver to reset it. :thumb:

Olley

 

[Lampie]

Hi Forestboy

Yes griffin fitted it, I called in to pick some bits up from Linda at stateside on way down and parked in Griffins yard overnight surrounded by some lovely RV's . They fitted it the next morning and I came home in bad snow.

It is truely great, even in swiss this year on the way back from italy on a 3 amp supply worked. I have not had one instance of it tripping a breaker since it has been fitted. By yellow box 110v transformer type boxes it is not cheap, however if yours is not one of these type the soft start part I don't think would be too bad to add in. They changed the lot for me. The whole thing was under 400.00 and I sold the yellow box construction one for 100.00.

I am glad I had it fitted. Next RV will do the same.

Olley

If your thinking of it give them a call it's well worth it, it all depends on what you already have transformer wise. If the transformer is of the right type they can just add the soft start bit.

Regards

Lampie

 

[olley]

Hi Lampie, yes it is, 240 to 110 and 110 to 240. but so far apart from that one instance no probs.

On low power sites I plug the charger in only and let the inverter power everything, so I shouldn't have a problem there either.

Olley