why I need Power Inverter With Built-In Battery Charger if I can have DC Pump? 3

[eurasian]

Can any nice people tell me why the existing of Power Inverter With Built-In Battery Charger is necessary if I can have DC Pump? because my customer asks me to search for DC pump they want to get rid of inverter, i am not sure if it can work out since the power supplier is generally in AC.

Thanks for your help

 

[MikeHalloran]

Your customer may be shocked at the price of DC pumps.

... if AC pumps are available for the same service.

... the nature of which you have not revealed to us.


This would probably be a good time for you to work up a spreadsheet to calculate the lifecycle costs to the customer of AC vs. DC pumps.



Mike Halloran
Pembroke Pines, FL, USA

 

[eurasian]

Thanks Mike,
I understood that DC Pump Price will be shocking
Lifecycle cost, AC is cheaper than DC? but they are asking about brushless DC pump, is it also very costy in price and lifecycle cost?

and I heard DC pump must work with a controller is that true? i heard a controller is even more expensive than a DC pump.

thanks for help.

 

[MikeHalloran]

The actual motor part of a typical brushless DC motor is hard to distinuish from a 3-phase AC motor. The 'control' is a 3-phase inverter, usually with variable speed.

My limited experience, with 'smart' air handler fans, basically fancy brushless DC motors with current sensors used to infer and control the airflow, or something, says the MTBF may be as small as five years. Brushes may not last that long, but they're cheaper to replace. Smart air handlers have been in the market for at least ten years, but so far nobody stocks replacement motors or controls; you have to buy a whole new air handler and throw away what you don't need.

Read up on the subject and pick a number different from mine if you can find better data, but don't assume that a brushless DC motor wil run forever.


Mike Halloran
Pembroke Pines, FL, USA

 

[ozmosis]

I'm not sure what sort of pump you are looking at but do you mean something like this from Grundfos?

http://us.grundfos.com/products/find-product/sqflex.html

 

[eurasian]

So I understood now is DC pump expensive and short life, anyway the AC pump is more economized, do I understand right?

This link from Grundfos that Ozmosis provided is saying that pump is compatible with both DC and AC power supply without requiring an external inverter,

How can a pump can accept both AC and DC without external inverter? does this pump belong to DC pump or AC pump?

Thank you guys for help.

 

[ozmosis]

Probably because it has an internal controller that you can connect AC too or you could connect directly a DC supply from your pv unit.

 

[BigInch]

Wiring, switches, equipment in general will be rated for a DC voltage of approximately 1/2 of whatever its AC voltage is, thereby considerably increasing cost of DC equipment of equal voltages.

Independent events are seldomly independent.

 

[eurasian]

Thank you guys