220v to 24v ?

[cornishcarlos]

Question about transformers... Crossy or anyone else with experience ?

Thinking about the options to power lighting (LED) plus water pump from 24v DC.. This is for a future project.

I am not particularly interested in pure solar power but more using the mains supply and converting. Possibly with batteries as a back up.

Want to maintain 220V for 1 A/C unit . Will be looking at solar water heater though.

Any thoughts, pros or cons ?

[cornishcarlos]

Didn't realise there is an Electrical forum !

Maybe one if the Mods could move this ?

Thanks

[RichCor]

You'll probably need to specify that you want to accomplish with the lamps and water pump.

If for a Water Feature and/or outdoor feature lighting then you'll have lots and lots of options.

[CharlieH]

MOVED TO Electrical forum.

[cornishcarlos]

Its for small, detached accom for guests or to rent out. Still undecided on actual design but would like to run as much as possible on 24v DC.

Only going to be small living area/bedroom and bathroom.

LED lighting would be for main room and bathroom plus couple on outside deck area.

Pump would be for shower and sink, similar to on a boat system.

I would like solar hot water tank on the roof.

If I brought the main supply in, then used 1 phase for A/C unit, 1 phase for a kettle and hairdryer, 3rd phase to a transformer to DC, would that work ?

Battery back up would have to be incorporated into that system.

[keeniau96]

Not a transformer but inverter for 220VAC to 24VDC. I have seen some of those at Amorn store here at Big-C in Phuket and at the Kee Hin company, which is the major electrical supply house here. Also at several marine supply shops (chandleries), cost can range enormously depending on the quality; I have seen them from 900 baht to 9000 kbaht.

For solar you will need the panel and a charge controller; I just installed a proper system on my friend's boat, simple but a bit tedious.

[cornishcarlos]

Thanks

Edited January 9, 2016 by cornishcarlos

[Litlos]

Just to keep it all accurate and help to not buy the wrong item. To go from AC to DC is called a power supply, to go from DC to AC is an inverter.

When looking at power supply sizing for a battery load the rule of thumb is the charging amps should be no more than 10% of the battery amp hours.

Solar chargers come with a regulator and an inherent 50% of the day charging cycle, this helps stop the batteries from overcharging. If charging continually from AC and the load is not applied fairly regularly the batteries can easily become overcharged and lose lifetime expectancy (that is the simplified explanation). If you are intending on having the batteries continuously on charge then you are better looking at something called a battery maintainer which automatically adjusts charging to suit the no load situation e.g. Ctek. There is a Thai reseller, but probably better to look at the main Ctek website.

You should be able easily use a single phase to run a charger. From the Ctek info for 24Vdc at 20Amp the input current is 3A at 220Vac. Yes I do like the Ctek products and have bought previously for both home and work.

Cheers

[RichCor]

I'm wondering what the benefits might actually be, over running an extra 220v branch circuit from your main house to the guest house.

Sure, you can lower some costs by using solar heated water, or compressed gas water Heater; low voltage/wattage lighting; etc. but it the residence only sees light use then you may not save much over just using off-the-shelf items designed for a 220v system. And I would think Solar Heated water system that's used infrequently would need the water pre-treated to keep the water from becoming a breeding ground.

On the other hand, I've read posts on ThaiVisa about people building or converting entire Australian households over in a similar style to living on a boat (or caravan).

[bankruatsteve]

To clarify: conversion from AC to DC is called rectification (or rectify). DC to AC is called inversion (inverter).