Solutions to load shedding

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I saw a 1000W inverter at Mica the other day, whereas they normally stock 300W. Is this a good idea for me to buy?
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Probably not - check if it is a "full sine-wave" inverter. If yes, then it would be great, but I suspect that Mica and most other chains only sell the so-called "modified square wave" inverters, and these are not appropriate for use with pumps.

Hennie
 
Even a Magnet drive pump?
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Especially a magnet drive pump (and almost all pumps are driven this way). The only pumps which won't be affected would be pumps such as the Tunze low voltage DC pumps, and units supplied through a transformer or controller.

he techie there said a normal pump should be fine, its when u get to play stations and other electronics that u have issues.
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IME it's the other way round - computers, play stations, etc. all have built-in switch-mode power supplies which converts the 230V AC into 5V & 12V DC. They don't need a very "pure" AC supply, in fact, many can operate on anything between 65V and 240V AC.

Pumps, on the other hand, work by converting the electro magnetic force into rotational force. The impellers are magnets, and there are field coils in the body of the pump which either attracts or repels the segments of the magnet. These pumps need to have a "pure" sign-wave AC 50Hz supply to work optimally. The "modified square-wave" converters actually supply short bursts of 230V DC power (at approximately 50Hz), which "looks" similar to AC in that there are "+230V", "0V" and "-230V" peaks and troughs, but the voltage does not rise and fall gradually, as with a "pure" sign wave supply. This leads to the electro magnets not working optimally, and also (perhaps more importantly), the extended high voltage "peaks" result in the creation of more heat in the system. combined, you will find that your pumps will run warmer, and will tend to "chatter" and supply a smaller volume of water. In the end, the wiring in the pump can become so hot that the pump can burn out - not worth the risk, IMHO.

Hennie
 
Agree 100% with Hennie,

I would not recommend using anything other than "Pure" sine wave inverters, most of these unit you bay from chain stores are "CHEAP AND NASTY", If you connect it to a oscilloscope you'll see what I'm tanking about.

You could also experience shafts and impellers breaking!
 
Well thanks for the info, my understanding was that pumps like the Haleia 6540 had the built in transformer inside which would regulate the current in anycase?

Also when u mention that the pump eventually failing, this would be when u actually running on battery backup...not while running on normal power via the backup unit?

By the way, there is no clatter noise when my mains power goes off and the backup unit kicks in.
 
Adee said:
Well thanks for the info, my understanding was that pumps like the Haleia 6540 had the built in transformer inside which would regulate the current in anycase?

Also when u mention that the pump eventually failing, this would be when u actually running on battery backup...not while running on normal power via the backup unit?

By the way, there is no clatter noise when my mains power goes off and the backup unit kicks in.
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AFAIK no pumps have build in transformers, as they run on 220V there would be no need for one, and have no AVR (automatic voltage regulator), As Hennie said, some of the top end pumps like the Tunze and Vortex have transformers, but its because they are low voltage DC pumps and there transformer is external, not in the pump.

Some pumps might have a Thermal Protection Device, but probably only a couple of them?

The pumps will be ok if running on mains power, the damage would be caused when powering from the NON-PURE sinewave inverter, however, the pump may still fail while running on mains power if it has sustained prior damaged while on the inverter.

Hope that clear it up?
 
lIghty said:
AFAIK no pumps have build in transformers, as they run on 220V there would be no need for one, and have no AVR (automatic voltage regulator), As Hennie said, some of the top end pumps like the Tunze and Vortex have transformers, but its because they are low voltage DC pumps and there transformer is external, not in the pump.

Some pumps might have a Thermal Protection Device, but probably only a couple of them?

The pumps will be ok if running on mains power, the damage would be caused when powering from the NON-PURE sinewave inverter, however, the pump may still fail while running on mains power if it has sustained prior damaged while on the inverter.

Hope that clear it up?
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thanks Lighty, whats the price differential between these square wave and pure sine wave inverters? (thumbsuck)
 
Well ok, does makes sense....anyway if the pump does decide to go, would have to change the inverter.

Was thinking then off just adding another return pump that would run off a transformer (like the vortech and tunze's) then using a 12 volt powered return pump, complement my current return pump..so in an outage just the 12 volt return pump would keep going.
 
mnd123 said:
thanks Lighty, whats the price differential between these square wave and pure sine wave inverters? (thumbsuck)
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Quite alot as there is a big difference in design.

Pricing examples:

Modified / simulated / square wave

300w 12V = +- R400-500
600w 12V = +- R800


Pure Sinewave

300w 12V = R1000+
600w 12V = R1500+

These are just rough prices.
 
You can still use your large inverter & just try find a smaller true sine inverter for your pumps only.

Will lights & heaters not work with the modified inverter?

thanks Mark
 
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