Where can I get a 72V DC --> 240V AC sine-wave Inverter?

[sheep]

Hi all!

Can anyone suggest a company who can supply a good quality sine-wave inverter to convert 72V DC to 240V AC for a reasonable price, and who can ship to the UK? I only need about 2000W maximum.

I bought one from China via eBay, and unfortunately it failed with a flash and a bang after just 5 minutes running at 80% capacity. To be fair to the Chinese supplier, they have offered to repair the inverter for me, but I have lost confidence in its quality, so have asked for a refund instead.

72V seems to be an unusual input voltage requirement, and few suppliers list these as a standard product, so I'm guessing it will have to be a custom build, unless anyone knows better?

I have found a couple of companies who make models with 72V input, but they seem to be designed for use in the railway industry, and these are extremely expensive

Thanks in advance for any hints.

[Mike90250]

Sadly, what you found out, is that anything over 50V, is gong to be for industrial use. You MAY be able to find a surplus 10 - 20Kw computer UPS that runs at high voltage. Best I can do.

[sheep]

Sadly, what you found out, is that anything over 50V, is gong to be for industrial use. You MAY be able to find a surplus 10 - 20Kw computer UPS that runs at high voltage. Best I can do.

Thanks for the reply, Mike.

I have considered modifying a surplus UPS, but sadly these seem to have the same problem - 72V is an unusual DC battery voltage. They seem to jump from 48V to 110V input with nothing in between.

I have an old APC SmartUPS unit (SUA3000RMXLI3U) whose battery voltage was 48V, and I have discovered by experiment that this will work on 72V, but it's so far outside its design limits I would not be happy about using it like this long-term (and its alarm buzzer sounds continuously!). I suppose it is testament to its build quality that it can work at all!

[paulcheung]

Can the DC volts drop to 60 volts? most of the quality 48 volts inverter can safely operates at up to 62 volts. Just a thought.

[bcroe]

Hi all!

Can anyone suggest a company who can supply a good quality sine-wave inverter to convert 72V DC to 240V AC for a reasonable price, and who can ship to the UK? I only need about 2000W maximum.

I bought one from China via eBay, and unfortunately it failed with a flash and a bang after just 5 minutes running at 80% capacity. To be fair to the Chinese supplier, they have offered to repair the inverter for me, but I have lost confidence in its quality, so have asked for a refund instead.

72V seems to be an unusual input voltage requirement, and few suppliers list these as a standard
product, so I'm guessing it will have to be a custom build, unless anyone knows better?

I have found a couple of companies who make models with 72V input, but they seem to be designed
for use in the railway industry, and these are extremely expensive

One work around would be a 72V to 60V buck DC-DC converter. The 1 KW units I built could be held in
one hand, and efficiency is pretty good (because 60/72 of the power just flows straight thru). A 2 KW
version might like to be a 2 or 3 phase (several smaller working in parallel), I see chips to support this
are now off the shelf. The problem; likely custom design. Bruce Roe