UPS System Advice

[dan091]

Hi Guys,

I hope this is the right place to post? I'm looking at building a ups system comprising for deep cycle leisure batteries and an inverter plus a few more bits and peices etc. The setup would go something like this:

240vac > car battery charger > 12vdc > batteries > 12vdc > inverter > 240vac > pcs

Currently I have a small problem as in my rcd breaker can be tripped due to the machines being plugged in sometimes. 99.99% of the time its fine and without any problems. I have been told this is due to machines etc having high earth leakage.

My question is if I were to run an isolation transformer would that prevent eath leakage going back into the ring main and tripping the breaker and esentially allowing me to run my current machines and more machines without the breaker tripping?

Any advice would be appreciated.

Daniel

 

[Resqueline]

Yes, on all accounts.
Both the charger and the inverter would act as isolation transformers here provided you're running double conversion / online topology, saving you the separate isolation transformer you'd need if running an offline / standby or line-interactive system.

 

[dan091]

Yes, on all accounts.
Both the charger and the inverter would act as isolation transformers here provided you're running double conversion / online topology, saving you the separate isolation transformer you'd need if running an offline / standby or line-interactive system.

I see thank you.

Daniel

 

[dan091]

Resqueline,

Does the following diagram below conform to "double conversion / online topology"?

240vac > car battery charger > 12vdc > batteries > 12vdc > inverter > 240vac > pcs

I can't see any other way of setting it up really.

Daniel

 

[Resqueline]

Yes, that's what it is, unless the battery charger is too weak to supply the full power to the PC's + recharging, thus necessitating a relay bypassing the 240 straight to the PC's when mains is present - in which case it would be an off-line / standby system.

 

[dan091]

I managed to hook up 5 pcs on the following:

20amp charger, 800watt inverter

However when adding the sixth the inverter squeeks about low power. These machines were old and the power used was 230-260 watts with 5. I'm happy to say the mains breaker doesn't trip when running the machines so that solves my problem howevr I need to move my slightly more powerful servers onto a system like this.


Update: I did some working out and found that I can only get 240watts out of the 20a charger. Looks like I'll need something abit bigger or more systems like this maybe.
Daniel