Axpert invertors

So, I decided to expand the wiring in the garage where the Axpert is mounted. I wasn't happy with the layout, so I decided to put up a proper sub-DB. This is what it looks like:

20150704_183316.jpg

Top row: Main switch DP breaker (fed from main DB), power indicator, breaker feeding changeover, then, earth leakage with 2 breakers for local plugs.

Bottom row: 4-way changeover switch wired to be used as bypass when inverter fails/being serviced, breaker from changeover (main breaker for dedicated section), power indicator, breaker feeding back to main DB, local dedicated plugs, local lights.

The Axpert is wired to and from the bottom of the changeover switch.

My inverter output neutral-earth bonding is done right at the Axpert's output terminals:

20150704_183216.jpg

Comments welcome
 
Axpert installed on only one phase of 3 phase power

Not sure if this has been answered somewhere else but here goes; I currently have 3 phase power supply to my house. I am looking to install an Axpert 5kw on one of the phases to run the essentials like the lights and security systems. Can this be done?
 
silver phantom said:
Not sure if this has been answered somewhere else but here goes; I currently have 3 phase power supply to my house. I am looking to install an Axpert 5kw on one of the phases to run the essentials like the lights and security systems. Can this be done?
Click to expand...

IMHO, yes it should work. As long as there are no 3 phase appliances in your house, or, you have to disconnect them with a contactor or relay when Eskom fails.

I can't say whether this is legal though. Someone else might chip in here. Savage?
 
No 3 phase appliances or equipment installed in the house. Tried looking for information to see if this is legal or not, but cannot find any.
 
silver phantom said:
Not sure if this has been answered somewhere else but here goes; I currently have 3 phase power supply to my house. I am looking to install an Axpert 5kw on one of the phases to run the essentials like the lights and security systems. Can this be done?
Click to expand...

My flat has 3 phase. Feeding only my lights and a set of plugs from my inverter.

Open up your DB board and look at how the phases are utilized. Typically you'll have the 3 phases split among various plugs, lights, geyser. They are just using a single phase and can therefore run from a single phase.

Generally your stove will be 3 phase. Even thought the stove may be wired as single phase (ie> plates split among two phases and stove another phase), you cannot split it. Anything with a single pole breaker is safe to run from a single phase. Anything with a 3 pole breaker is probably running on single phase anyway, but you should not, under any circumstances run it on single phase.

Older homes used to have 3 phase stoves and such. Any modernized home will likely just split everything among the phases and be single phase anyway. Doesn't mean you should wire it as single phase tho.

Post of pic of your breakers then we can talk more.
 
Last edited:
DollyAAAA said:
So, I decided to expand the wiring in the garage where the Axpert is mounted. I wasn't happy with the layout, so I decided to put up a proper sub-DB. This is what it looks like:

View attachment 231434

Top row: Main switch DP breaker (fed from main DB), power indicator, breaker feeding changeover, then, earth leakage with 2 breakers for local plugs.

Bottom row: 4-way changeover switch wired to be used as bypass when inverter fails/being serviced, breaker from changeover (main breaker for dedicated section), power indicator, breaker feeding back to main DB, local dedicated plugs, local lights.

The Axpert is wired to and from the bottom of the changeover switch.

My inverter output neutral-earth bonding is done right at the Axpert's output terminals:

View attachment 231438

Comments welcome
Click to expand...

Looks good.

I like that you have your neutral/ground bonding in the equipment :)

Just to be sure, your neutral and ground were definitely at the same potential?
You measured this before joining them?
Many inverters have a center tapped transformer so the ground isn't at the same potential as the neutral.

Do you have a Earth Leakage on your DB supplied with alternate power? (Looks like it)
- I have a Main Switch and EL for my alternate power source. So my alternate power has a separate circuit board from which plugs and lights are wired.
- My alternate power is also on the house EL when powered from Eskom
What are you using to switch over?
- I am using a 3PDT relay. Ideally I want to switch to a 2x2PST contactor with mechanical interlock (much more expensive solution)
How are you dealing with the fact that your inverter and mains are not synchronized (is this the case?)
- In my own case my change-over switch was very quick and I had to add a delay to prevent a dangerous situation. I only realized this after looking on my Oscilloscope.

Just some general questions.

DB is very well wired, good job man. You an electrician?
 
Gnome said:
Just to be sure, your neutral and ground were definitely at the same potential?
You measured this before joining them?
Many inverters have a center tapped transformer so the ground isn't at the same potential as the neutral.
Click to expand...

The ground and neutral were not on the same potential. The supply from the inverter (in battery mode of course) is floating. Savage suggested bonding the neutral to earth on the output as he does on his installs.

Gnome said:
Do you have a Earth Leakage on your DB supplied with alternate power? (Looks like it)
Click to expand...

No, I don't. The EL on the top row is for normal plugs in the garage. My dedicated plugs are SANS 164-4 (red dedicated), so no earth leakage required.

Gnome said:
- I have a Main Switch and EL for my alternate power source. So my alternate power has a separate circuit board from which plugs and lights are wired.
- My alternate power is also on the house EL when powered from Eskom
What are you using to switch over?
Click to expand...

I don't switch over. The Axpert does all that. When Eskom is supplying, the Axpert bypasses internally, when Eskom fails, the inverter starts up and takes over, so no interruption - like a UPS. My bypass switch in the DB is for maintenance.

Gnome said:
- I am using a 3PDT relay. Ideally I want to switch to a 2x2PST contactor with mechanical interlock (much more expensive solution)
How are you dealing with the fact that your inverter and mains are not synchronized (is this the case?)
Click to expand...

I don't believe it's switches back and forth synchronised. All I notice is a slight flicker in the lights, but TV & PC never hiccups.

Gnome said:
- In my own case my change-over switch was very quick and I had to add a delay to prevent a dangerous situation. I only realized this after looking on my Oscilloscope.
Click to expand...

I'd love to scope the Axpert's output, but can't lay my hands on one right now.

Gnome said:
DB is very well wired, good job man. You an electrician?
Click to expand...

No, just a hobbyist. Thanks for the kind words.
 
DollyAAAA said:
The ground and neutral were not on the same potential. The supply from the inverter (in battery mode of course) is floating. Savage suggested bonding the neutral to earth on the output as he does on his installs.
Click to expand...
Hmm interesting, I was wondering if that is a good idea.

DollyAAAA said:
No, I don't. The EL on the top row is for normal plugs in the garage. My dedicated plugs are SANS 164-4 (red dedicated), so no earth leakage required.
Click to expand...
I have those plugs also, but installed an EL anyway, they cost about R700 (CBI QA17C)

DollyAAAA said:
I don't switch over. The Axpert does all that. When Eskom is supplying, the Axpert bypasses internally, when Eskom fails, the inverter starts up and takes over, so no interruption - like a UPS. My bypass switch in the DB is for maintenance.
Click to expand...
Oh interesting.
What kind of contactor is that?
How is it powered (one coil, multiple coils?)
Where did you get it and what did it cost?

DollyAAAA said:
I don't believe it's switches back and forth synchronised. All I notice is a slight flicker in the lights, but TV & PC never hiccups.
Click to expand...
Then it probably is synchronized to some extent ;)

The flicker is due to the AC interruption, if it weren't synchronized you would have a over voltage situation which could damage your equipment. Since it has an integrated change-over switch, they either ensure it doesn't switch too fast or ensure it is synchronized.

DollyAAAA said:
I'd love to scope the Axpert's output, but can't lay my hands on one right now.
Click to expand...
It is pretty awesome to see. I had a look at my APC Smart-UPS, Eskom power, APC RS UPS and my Cotek Pure Sine inverter. Eskom has some distortion on their power. APC RS is pretty much square. APC Smart UPS and Cotek are perfect sine. Was cool to see the change-over on the scope!

DollyAAAA said:
No, just a hobbyist. Thanks for the kind words.
Click to expand...
Cool, same for me. I spent quite a bit of time wiring my DB (it was a mess). It takes a lot of time to make it look decent, so can appreciate the effort.
 
Gnome said:
I have those plugs also, but installed an EL anyway, they cost about R700 (CBI QA17C)
Click to expand...

Also might be doing it anyway. The M.E.S. DIN rail part is about R200.

Gnome said:
Oh interesting.
What kind of contactor is that?
How is it powered (one coil, multiple coils?)
Where did you get it and what did it cost?
Click to expand...

It's a 4-pole DIN rail mounted changeover switch. No contactor/coils. It's got 3 positions: 1-off-2. Part no SFT 440, made by Hager. ACDC makes a slightly cheaper one. Also, I could have gotten away with a 2-pole together with an input breaker.

Gnome said:
Then it probably is synchronized to some extent ;)

The flicker is due to the AC interruption, if it weren't synchronized you would have a over voltage situation which could damage your equipment. Since it has an integrated change-over switch, they either ensure it doesn't switch too fast or ensure it is synchronized.
Click to expand...

The Axpert has a configurable switch delay (10ms or 20ms)
 
DollyAAAA said:
Also might be doing it anyway. The M.E.S. DIN rail part is about R200.
Click to expand...

Wow CBI breakers are expensive in comparison then :o

Bought a 3 phase EL @ R1470 for my place :'( (hence having an extra single phase EL for use with my backup power)

Thanks for sharing. Was good to see that someone else's setup.
 
Gnome said:
Wow CBI breakers are expensive in comparison then :o

Bought a 3 phase EL @ R1470 for my place :'(
Click to expand...

Also found out the other day. All the DIN rail stuff is cheaper than the CBI/SAMITE stuff. You can try Onesto, M.E.S. and Chint.

Not sure about the quality though.
 
Gnome said:
Bought a 3 phase EL @ R1470 for my place :'( (hence having an extra single phase EL for use with my backup power)
Click to expand...

That's for an E/L with overload protection, i.e. a 35mA / 40A E/L. E/L will trip if more than 35mA is leaked, OR if more than 40A flows through the breaker (similar to a circuit breaker).

As soon as you add overload protection to a E/L, they do become expensive. It's not only CBI.
 
Off the topic of Axpert, on the topic of inverters... saw a tweet that got me thinking.
The power we get from Cahora Bassa is supplied as DC, at 533kV and provides up to 1920 MW.
It lands in Joburg at the Apollo substation which inverts it to 50hz AC.

That must be one MOER of an inverter!
 
savage said:
No - those are LED lamps - you buy them like that. Many options available in terms of DIN rail mounts.
Click to expand...

Thanks
Is there adaptors available from crabtree breakers to din rail ?
Our db is 40 years old :(
 
thehuman said:
Thanks
Is there adaptors available from crabtree breakers to din rail ?
Our db is 40 years old :(
Click to expand...

You do get adapters that fit to a minirail (CBI) that'll take a DIN rail component. White plastic type thing. Not sure how the clearances will work.

Alternatively, you replace part of your rail bracket with DIN rail. You can buy them in lengths and cut to size.
 
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