Isolation Transformer: Victron vs Mastervolt vs Charles

[pbiJim]

Originally Posted by DotDun

It also states that a 50hz unit cannot operate at 60hz.

This is the first time that I have seen that sort of statement. This disqualifies something that I have believed true for many years. I can only guess that in this case it's because of a problem with starting torque. If anyone else has encountered 50hz equipment that does not run on 60hz, I'd like to hear more about it.

[DotDun]

Originally Posted by pbiJim

This is the first time that I have seen that sort of statement. This disqualifies something that I have believed true for many years. I can only guess that in this case it's because of a problem with starting torque. If anyone else has encountered 50hz equipment that does not run on 60hz, I'd like to hear more about it.

It's probably more to do with the freon pressures created by the compressor running 20% faster than the actual motor.

FWIW, I ran a 50hz shop vac at 60hz for several years with no problems, in fact, it had great vacuum!

[pbiJim]

Originally Posted by DotDun

It's probably more to do with the freon pressures created by the compressor running 20% faster than the actual motor.

FWIW, I ran a 50hz shop vac at 60hz for several years with no problems, in fact, it had great vacuum!

This has me curious now. I had thought that freon pressure would not be an issue because I was thinking of AC systems with a cycling pressure relief system. What you say would be true of systems with a fixed orifice valve type bleed down system. Both types exist today, but I don't know which is more common in marine AC units. I had not considered the possibility of an orifice valve system. Good point. Thank you.

I had thought that starting torque may be an issue because a 50 hz motor (not 50/60 rated) will have more impedance than a 60hz motor of the same size & therefore not pass as much current at 60hz & therefore not have as much torque at 60hz. These days, with appliances going green & trying to qualify for energy star ratings, the motors may be engineered down to a gnat's sphincter & may not have enough extra torque capacity engineered into their design to start the compressor under load with the reduced torque. That was my guess anyway. It was just a guess.

I'd like to hear about more examples of 50hz equipment not working on 60hz if anyone knows of them. The only other one that I know of was a clock that kept time by the frequency of the power that was supplied to it.

[Palarran]

To complete my part of this thread, I have just ordered the Victron 32 amp Auto Transformer. It was the solution per the NA Victron technical rep.

Here is the text:
The autotransformer will do the job here.
The pass trough on 240vac is the 100amps.
The transformer is 32amp, so there can be a maximum of 32 amps through the center tab.

In the EU this means you will have max 23kw on the 230vac side and 3.6 kW total on the both 120vac legs.

In the states you will have 3,6kw on the 240vac legs when 120vac single leg is coming in.
When split phase comes in there is again the limit of 100amps.


Isolation is NOT what the transformer does , so if that's needed a isolation transformer must be installed before the auto transformer
( or a galvanic isolator might do the trick too )

[Morrissey]

Hope your new Victron gear works for you. My only complaint was delivery time in the USA, but stuff did arrive eventually. Notwithstanding, I have two Charles transformer units installed and they are working fine. One is used for isolation, and the other for step-down.

My system - see attached - can take any shorepower and charge the batteries as well as supply AC for distribution. Incoming frequency is not changed, so when I have 230V 50Hz shorepower then the few remaining 120V 60 Hz items get 115V 50Hz. It should only matter for inductive loads - resistive loads such as the toaster dont matter at all. Having said that, my 120V 60Hz washer, and also the dryer (both Whirlpool models), have been working OK. Now that I'm back in Australia I will change them out to 50Hz appliances. My Uline Icemaker spec says 60Hz but seems OK at 50Hz.

No generator installed, just 1800 W of solar. Each engine has a 200A alternator as well. No problems keeping battery bank charged.

[botanybay]

The question was asked if anyone saw differences running on 50hz or 60hz in general for most equipment. With the recent installation of a larger inverter and battery charger I can now go back and forth between 230V 50hz and 208/240V 60hz. Note that about half of the US "high voltage" docks are two 120V legs which are 120 degrees out of phase and (208V) the other half are two 120V legs which are 180 degrees out of phase (240V). Right now I am on a 208V dock so if I am running the isolation transformer 1:1 I get about 214V out of the transformer. I have not yet tried 120V input using 1:2 stepup of the voltage which would be like using a 240V US dock. The majority of the equipment was setup for England in 1990, however, most was selected to be 50/60 hz compatible and the power limitations are 230V +/- 10% or 207V - 252V. The generator for the boat is 230V and so I have been able to run equipment that way on 230V 50hz but with the noise of the generator it is difficult to determine if the equipment is making any noises differently than on 60hz So, a quick run down of observations: 1) Microwave (not rated for 60hz) 230V 50hz - Works exceptionally well, heats water in a cup very quickly (30 seconds) 208V 60hz - Works but heats water slowly similar temp to above in 5 - 6 minutes 2) Refrigeration Compressor (AC holding plate ~1500 watt compressor) 230V 50hz - Works very well rarely makes a bit of noise during pump down cycle 208V 60hz - Significant amount of "pinging", especially early in the pump down cycle. Suspect that the lower voltage does not provide enough torque to work against refrigerant load when wide open. 3) Air conditioning system 230V 50hz - Works very well but not enough time on hardware to be sure the issue with 208V 60hz does not show up. 208V 60hz - The evaporator slowly ices up starting closest to the compressor. Most likely slightly undercharged. Both units (16,000 btu) have the issue. 4) Washing machine (not rated for 60hz) 230V 50hz - Near end of life, would function correctly for small washing loads but moderate loads (3 towels) the belt would slip. 208V 60hz - Would run but spin cycle would stall 5) Battery charger (old style constant voltage unit - 1997 vintage) 230V 50hz - worked fine 208V 60hz - worked fine - somewhat lower peak output 6) Hot water heater 230V 50hz - very quick heating 208V 60hz - as expected somewhat slower heating, lower voltage gives lower amperage combination drops performance. Barely noticeable. Hope this is helpful. With the inverter able to handle house loads most of the time I am finding that the equipment in general sounds better on 230V 50hz than on 208V 60hz. I don't yet have a feel for how much of this is the lower voltage (208V vs 230V) or the frequency. I have been told before that when running 230V 50hz equipment on 60hz power that having slightly reduced voltage can help matters. I have not yet tried running 240V 60hz power on the equipment for extended periods of time. However, when plugged into some docks I have gotten 240V. The isolation transformer is probably going to boost that into the 245V range which is going to be higher than I have seen previously.

[Night_Sailor]

Originally Posted by isobelk

we have used a charles for 5 years. it does hum a bit when loaded up, but not bad even though it is in the locker near the sleeping berth.

As to heat, it will get warm, but not too hot to touch.

Don't know how you will get 'real' world comparisions as most on this forum will have only one unit installed, and the feedback is totally subjective.

good luck

I will second this--my experience is the same. I'll add my zincs last avery long time. I still change them annually--could probably go two years or more.

[Palarran]

As a follow-up to the installation of my system, I ended up installing a Victron 7000w Isolation Transformer that fed a Victron Autotransformer in July of 2014. The system worked great until last week when the Iso transformer failed. Victron has updated their warranty on products to 5 years but unfortunately the Turks who installed it used a 2012 manufactured transformer so I'm out of luck on warranty as it's not retroactive. So I've ordered a new one which will cost another 1000 euro.

IMO, I'd have been better with the Charles Isolation Transfomer going into the autotransformer. No circuit boards and at this point - about 1/3 the cost.

[DotDun]

Originally Posted by Palarran

As a follow-up to the installation of my system, I ended up installing a Victron 7000w Isolation Transformer that fed a Victron Autotransformer in July of 2014. The system worked great until last week when the Iso transformer failed. Victron has updated their warranty on products to 5 years but unfortunately the Turks who installed it used a 2012 manufactured transformer so I'm out of luck on warranty as it's not retroactive. So I've ordered a new one which will cost another 1000 euro.

IMO, I'd have been better with the Charles Isolation Transfomer going into the autotransformer. No circuit boards and at this point - about 1/3 the cost.

Did the core fail? From the picture, it appears to be soft-start resistors. If so, those should be replaceable at the component level.

[Saltyhog]

Originally Posted by DotDun

Did the core fail? From the picture, it appears to be soft-start resistors. If so, those should be replaceable at the component level.

Agreed! If that's all that failed, you should be able to repair it for less than $10. What event proceeded the failure? My question would be why did that component fail in the first place. From the pic, it looks like there is something else burned up at the end of the resistor, not the resistor itself. Does not look difficult to repair. Of course it all hinges on the transformer itself being ok. If the windings are burned then a total loss.

[Palarran]

I'm sure someone could repair it, but it won't be me. The Greek distributor said that if I can come up with an original receipt then Victron might warranty it. If not, over the winter I'll have it sent back to Victron for repair at my expense and keep it as a spare.

As far as why it failed, I can only guess that the load was too close to the max for too long and it overheated. My gut from the beginning was to go with a non-electronic transformer and I should have. But the stuff looks pretty cool mounted on the wall.

[DotDun]

Certainly understand not wanting to repair it.

But, but, but, the soft-start circuity is simply 2 current limiting resistors and a latching relay. The resistors limit the in-rush load for the 10-20msec. it takes for the relay to close.

A quality core will run full capacity 24/7/365, and I believe Victron has that one circuit breaker protected. Unless lightning or other power surge got into it, the core is probably OK.

[Saltyhog]

It could very likely be the relay that failed. If the relay does not close, the soft-start resistors will remain in series with the primary of the transformer. When any substantial load is applied to the secondary, those soft-start resistors will "poof".