Need a 220v converter for my new VFD - How many watts?

Thread Starter

ElectromagnetNewbee

Joined Jul 13, 2014
69
So i just purchases this VFD shown here:
Sanven 5hp 4kw 220-250v Variable Frequency Drive Inverter VFD

http://www.amazon.com/gp/product/B00DRRQID6/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1

I need to convert my current 110 V into 220 V for this device, but not sure how many watts I need?

How many watts would a transformer/converter need to run this VFD? It says 4kw so do I need a 4000 watt transformer? or can I use a 1000 watt transformer/converter??

Or does the 4kw mean the power output for the VFD, and not the input power required???
 

MaxHeadRoom

Joined Jul 18, 2013
28,686
5Kw is the capacity it is capable of, if you have allowance to spare this does not mean it will always draw 5Kw, just what you demand of it.
Huanyang is not the highest quality VFD out there.
But you could also install a 240v line from the power panel if you are located in N.A.
Max.
 

inwo

Joined Nov 7, 2013
2,419
+1

Need a new circuit anyway. Unless you have a 30-40 120v circuit available.

What size motor.

There are 120V input vfds that output 3ph 240 volt. Only up to about 1.5 hp, I believe.
 

inwo

Joined Nov 7, 2013
2,419
What is the load and duty cycle.

Transformers can be overloaded safely.

An oil type 200% and dry type 150% for short periods.

Check the specs. Not over 1-3 hours for sure.

The 1000 would only be 1/2 size at best. Don't do it!
 

MaxHeadRoom

Joined Jul 18, 2013
28,686
Apartments are notoriously bad when it comes to adding things like power circuits.
If it has its own electric clothes dryer circuit, you could put an extension from that, just cannot do laundry and work the machine at the same time.
Also the stove circuit, but may be a little inconvenient!
You must have a tolerant Landlord to be able to operate a 5hp machine?
Max..
 

inwo

Joined Nov 7, 2013
2,419
That's not a bad Idea.
Just be sure to fuse properly and use the correct size wire if tapping a high current source.

Last winter a neighbor tapped his range outlet for a baseboard heater in the room above the kitchen.

I helped him after the fact, showing him how to connect thermostat.
Would have helped him more, but I only left him with a stern warning to get some fusing at the transition of the 50A circuit to #12 awg.

edit:
A dryer tail to the vfd might take care of the need for disconnect and fuses.
 

tcmtech

Joined Nov 4, 2013
2,867
Some things need far more clarification here.

First off is your air conditioner a three phase unit to begin with and if not what are you doing with the 4 KW VFD unit?

Second if it was intended for your air conditioner what voltage and amp draw is listed on it name plate and is it rated for a single or three phase input?

Third if you only need to boost your voltage from 120 to 240 you can get aways with using an auto transformer that is half the VA rating of the load its powering.

Fourth if you are trying to run a 240 VAC air conditioner unit from a low capacity 120 VAC source it will likely never work.

Your best option if you are needing a fair capacity 240 VAC source would be to either use a dedicated 240 volt feed from a dryer of stove like others mentioned or cheat a bit and find two 120 VAC circuits that are 180 degrees out from each other and cheat to get your 240 VAC by feeding from both circuits hot lines which will give you a 120:0:120 circuit with a 240 split between the two 120 sides.
 

jpanhalt

Joined Jan 18, 2008
11,087
One question is why do you would need such a large VFD in an older apartment?

Second, real estate law is one of the most arcane specialties of law. Residential is worse than commercial. It is not hard to think of several reasons the apartment owner would not want you to have a 220V line pulled. In fact, your anticipated use for that motor could get the owner into deep trouble with city zoning.

Your very first step, assuming you don't want to be evicted, is to discuss your plans with the apartment owner. Don't anticipate a supportive reply.

John
 

Thread Starter

ElectromagnetNewbee

Joined Jul 13, 2014
69
Your best option if you are needing a fair capacity 240 VAC source would be to either use a dedicated 240 volt feed from a dryer of stove like others mentioned or cheat a bit and find two 120 VAC circuits that are 180 degrees out from each other and cheat to get your 240 VAC by feeding from both circuits hot lines which will give you a 120:0:120 circuit with a 240 split between the two 120 sides.

love this idea!! :) just want i needed to know.
 

Thread Starter

ElectromagnetNewbee

Joined Jul 13, 2014
69
Keep in mind that you will have to keep the load right down on the rest of these two 120v circuits as they will only have a 15amp breaker behind them.
Max.
oh, that is good to know. Perhaps I should just order the Transformer/converter.

So what wattage im thinking is 2000 or 3000 watt. think my power lines can handle that and it will supply the VFD with the power that it needs and give me at least 15 amps of output...

So what wattage should I go with yall?
 

inwo

Joined Nov 7, 2013
2,419
Or an answer to post 12.
Is your load 3 phase?

A vfd isn't going to work with a single phase load.

I'm worried about where this thread is heading.
 

tcmtech

Joined Nov 4, 2013
2,867
love this idea!! just want i needed to know.
Granted as mentioned you may only have 15 amps per circuit to work with but at twice the voltage your line voltage drops will be far less of an issue if you are trying to pull 2+ KW off of a 240 VAC feed systems VS a 120 VAC single feed.

If you are planning to cheat as much as you can to get as much power as possible then I would suggest doubling up on the 15 amp 120 VAC lines on each half of the 240 VAC feeder you are making.

Doing that you could in theory allow you to pull ~6 KW without overloading any single circuit or wire line set or modifying a single electrical circuit in your apartment. Everything would be handled by extension cords going to a central 240 volt source point.
 

inwo

Joined Nov 7, 2013
2,419
Interesting theories.

If suggested to keep someone on life support in a doomsday scenario, I might agree.:D

Keep in mind that a novice may actually try these.:eek:

Keeping cool is not worth the risks of slapstick wiring methods, in the place where you sleep. IMHO
 
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