@Gerrie What do you think of TOMZN Automatic Transfer Switch (ATS). The product blurb claims to switch in under 8ms. Option for manual control as well. Seems very cheap compared to most other ATS's. A bit odd that the all the various current rating options (63A, 100A, 125A) are all the same price.

https://www.aliexpress.com/item/4000943742083.html?spm=2114.12010612.8148356.10.405c7e3833u3ti

 

Edited January 25, 20215 yr by recre8
added product image

It seems very cheap, It is odd that the different current ratings are the same price, it might be that the manufacturing process uses the same contacts rated for 125A even on 63A models and only the labeling differ. I have found that with some isolator switches where a 20A and 60A are also the same price. I still have tomzn and cannot find fault with the brand.

11 minutes ago, Gerrie said:

It seems very cheap, It is odd that the different current ratings are the same price, it might be that the manufacturing process uses the same contacts rated for 125A even on 63A models and only the labeling differ. I have found that with some isolator switches where a 20A and 60A are also the same price. I still have tomzn and cannot find fault with the brand.

I ordered two of them. Will check them out once they arrive and report back

So far so good. Eskom (after EL) is connected a Side-A/primary side. Inverter load (after EL) is connected as Side-B/secondary side to both units. The output of the first is used for my essential loads (lights and one plugs circuit that all my computers and wifi runs off). The second output is used for my non-essential loads (all other plugs circuits). My stove and geyser are left on only Eskom EL power. The non-essential ATS (automatic transfer switch) is set to manual so that I can make sure all power-heavy appliances are shutdown before switching over. The essential ATS is left on auto. The build quality of the product is really not bad, nice and weighty. I wouldn't feel comfortable pulling 100A through one, but in my current arrangement the most they will see is about 30A. I haven't noticed it getting hot at all, but the area where the relays are housed (not the contactor terminals) do get lukewarm.

The transfer time is sufficient that my PC, router and fibre ONT don't restart, but there is sometimes a visible flash on the lights. Automatic switching does make quite a loud noise, understandable given the heavy terminals they use inside and the fast switching time. 

Pro's:

• Build quality is better than I expected at this price. Terminals are solid, nice and large, although a cage terminal would have been better instead of a washer terminal.
• Price can't be beat, and I really couldn't find anything locally that does the same with the same transfer time.
• The unit is IEC/EN60947-6-1 certified. No SABS stamp obviously, but none of my other MCBs have SABS stamp either. 
• Switching time is fast enough to keep everything powered without restarting. 
• The integrated LEDs are very handy and actually suffice the SANS requirement for visual indicators to be used when alternative power is present. ( I actually bought 2x CHINT DIN Rail dual indicators for this, but they will now be repurposed).

Con's:

• 
  The highlighted part of the unit stand out further (distance from yellow plane to back of unit) than my other MCBs and my specific DB board cover got pushed out of little. A made the flap on the DB board cover that obscured the highlighted part a little bit more flexible to fix the issue. But still, not the same as other MCBs.
• The width of the unit isn't an exact multiple of 18mm (the width of a DIN "way", so fitting way covers/db blanks means there is a slight gap)
• Not available locally. Shipping to SA wasn't extremely expensive, but still a three week wait.

Some photos of the installation attached.

 

 

1 hour ago, recre8 said:

The essential ATS is left on auto.

How are you currently controlling the essential ATS on a timer or when Eskom fails?

1 minute ago, Gerrie said:

How are you currently controlling the essential ATS on a timer or when Eskom fails?

The essential ATS is in auto mode so it will automatically switch to Source B (inverter load) when Source A loses power. 

On 2021/03/03 at 7:32 PM, recre8 said:

So far so good. Eskom (after EL) is connected a Side-A/primary side. Inverter load (after EL) is connected as Side-B/secondary side to both units. The output of the first is used for my essential loads (lights and one plugs circuit that all my computers and wifi runs off). The second output is used for my non-essential loads (all other plugs circuits). My stove and geyser are left on only Eskom EL power. The non-essential ATS (automatic transfer switch) is set to manual so that I can make sure all power-heavy appliances are shutdown before switching over. The essential ATS is left on auto. The build quality of the product is really not bad, nice and weighty. I wouldn't feel comfortable pulling 100A through one, but in my current arrangement the most they will see is about 30A. I haven't noticed it getting hot at all, but the area where the relays are housed (not the contactor terminals) do get lukewarm.

The transfer time is sufficient that my PC, router and fibre ONT don't restart, but there is sometimes a visible flash on the lights. Automatic switching does make quite a loud noise, understandable given the heavy terminals they use inside and the fast switching time. 

Pro's:

• Build quality is better than I expected at this price. Terminals are solid, nice and large, although a cage terminal would have been better instead of a washer terminal.
• Price can't be beat, and I really couldn't find anything locally that does the same with the same transfer time.
• The unit is IEC/EN60947-6-1 certified. No SABS stamp obviously, but none of my other MCBs have SABS stamp either. 
• Switching time is fast enough to keep everything powered without restarting. 
• The integrated LEDs are very handy and actually suffice the SANS requirement for visual indicators to be used when alternative power is present. ( I actually bought 2x CHINT DIN Rail dual indicators for this, but they will now be repurposed).

Con's:

• 
  The highlighted part of the unit stand out further (distance from yellow plane to back of unit) than my other MCBs and my specific DB board cover got pushed out of little. A made the flap on the DB board cover that obscured the highlighted part a little bit more flexible to fix the issue. But still, not the same as other MCBs.
• The width of the unit isn't an exact multiple of 18mm (the width of a DIN "way", so fitting way covers/db blanks means there is a slight gap)
• Not available locally. Shipping to SA wasn't extremely expensive, but still a three week wait.

Some photos of the installation attached.

 

 

Thank you for sharing. Checking in more than a year later, how are these units treating you? Would you recommend this model or something else?

16 minutes ago, 0 |>\/\/3|<|<3Я said:

Thank you for sharing. Checking in more than a year later, how are these units treating you? Would you recommend this model or something else?

Hey. They are still going strong after more than a year. I don't use them to switch daily though, but they do cycle whenever loadshedding hits. Haven't had any issues. Only thing I have noticed is that the green LED isn't as bright as the red one, but that's about it. Otherwise I would recommend them. 

5 minutes ago, recre8 said:

Hey. They are still going strong after more than a year. I don't use them to switch daily though, but they do cycle whenever loadshedding hits. Haven't had any issues. Only thing I have noticed is that the green LED isn't as bright as the red one, but that's about it. Otherwise I would recommend them. 

Good to hear, thanks. Also won't be using it all the time, only to switch to my Goodwe ES inverter for backup during load shedding. The aim is to bypass inverter backup the rest of the time in order to do away with the essential load capacity limitation while there is utility power.

I'm noticing now that the ATS model I see online seems slightly different in appearance, referring to PV & Inverter instead of generator, as the alternate power source. Link below. Based on your experience with the brand, I might just give this a go.

https://e-glow.co.za/products/ats-toq5-63a-ac-2p-230vac-tomzn

11 minutes ago, 0 |>\/\/3|<|<3Я said:

Good to hear, thanks. Also won't be using it all the time, only to switch to my Goodwe ES inverter for backup during load shedding. The aim is to bypass inverter backup the rest of the time in order to do away with the essential load capacity limitation while there is utility power.

I'm noticing now that the ATS model I see online seems slightly different in appearance, referring to PV & Inverter instead of generator, as the alternate power source. Link below. Based on your experience with the brand, I might just give this a go.

https://e-glow.co.za/products/ats-toq5-63a-ac-2p-230vac-tomzn

Also, referring to the heading in the wiring diagram, 'DO-IT-YOURSELF BY YOURSELF' is a massive selling point  

8 hours ago, 0 |>\/\/3|<|<3Я said:

Based on your experience with the brand, I might just give this a go.

I can also add in on Tomzn as I still have the two change-over contactors in my DB. They don't do allot of switching these days I just leave them permanently energized, I upgraded to Sunsynk inverter and Sunsynk don't really need this functionality but it’s still nice to have. Only problem now is the prices have gone crazy to ship things into the country.

On 2022/07/22 at 3:06 PM, recre8 said:

Hey. They are still going strong after more than a year. I don't use them to switch daily though, but they do cycle whenever loadshedding hits. Haven't had any issues. Only thing I have noticed is that the green LED isn't as bright as the red one, but that's about it. Otherwise I would recommend them. 

On my newly purchased unit if it has switched over to B (Inverter) and then B fails it does not switch back to A (Eskom) when the A power returns. There is a click of a relay after about 2 seconds but nothing else. Is my unit faulty?

6 hours ago, RatBag said:

On my newly purchased unit if it has switched over to B (Inverter) and then B fails it does not switch back to A (Eskom) when the A power returns. There is a click of a relay after about 2 seconds but nothing else. Is my unit faulty?

Sounds like it might be. Post a photo of your setup.

Here is my test setup. In my post I misnamed the A = Inverter and B = Eskom(utility).

The ATS needs to have both power sources to switch to A. Surely this is not correct.

Would you also know if these units trip on overload.

13 hours ago, RatBag said:

Here is my test setup. In my post I misnamed the A = Inverter and B = Eskom(utility).

The ATS needs to have both power sources to switch to A. Surely this is not correct.

Would you also know if these units trip on overload.

It definitely sounds like your unit may be faulty or something inside isn't making contact. The 2 seconds delay for the relay also doesn't sound right. My units (100A units with generator and city power icons) switch instantly to whichever source is available. If both are available, it stays on Source A. If either one of the sources fail, it switches to the source with power. To my knowledge these units don't have overcurrent protection built in and rely on you having overcurrent protection upstream, which would be required anyways. 

I sent the unit back to the supplier and they said it is working correctly. I note that the Tomzn is marked PV/Inverter and City Power.

It has to have the Inverter supply permanently present to function. In some ways this might be suitable,  but it does not suit my application. Scenario: Inverter and City Power present, using City Power. City Power fails and the unit switches to inverter. Inverter runs out of power. No power Output. City Power returns and the unit does not switch back to City Power. If you are at the unit you can manually switch it back to City Power.

Hope this helps to clarify the functioning of the unit. 

1 hour ago, RatBag said:

I sent the unit back to the supplier and they said it is working correctly. I note that the Tomzn is marked PV/Inverter and City Power.

It has to have the Inverter supply permanently present to function. In some ways this might be suitable,  but it does not suit my application. Scenario: Inverter and City Power present, using City Power. City Power fails and the unit switches to inverter. Inverter runs out of power. No power Output. City Power returns and the unit does not switch back to City Power. If you are at the unit you can manually switch it back to City Power.

Hope this helps to clarify the functioning of the unit. 

@RatBag I cannot for the life of me see how the supplier can think this is normal behaviour. What would be the point of the unit then? If you still have the unit, there something you should perhaps test. These units are all the same, with different labels printed on them and they all "prefer" Source A. That the only reason I bought mine labelled as Generator and City Power (despite using it for solar)... simply because the City Power is labeled as Source A.

Try swapping your sources as per your example connection photo with Source A = Eskom and Source B = Inverter and see if that perhaps results in the functionality you are expect. I can tell your for certain that both my units follow the following logic when in Auto mode:

A present + B present = A selected
A present + B missing = A selected
A missing + B present = B selected
 

In my case (with solar connector to B at the bottom and eskom connected to A at the top) the unit wants to stay in position A. When eskom fails, it jumps to B and the moment Eskom returns, it will go back to A. 

EDIT: Video found on Youtube showing the behaviour I have (timestamp 4:10)

 

Edited September 22, 20223 yr by recre8

9 minutes ago, recre8 said:

@RatBag I cannot for the life of me see how the manufacturer can think this is normal behaviour. What would be the point of the unit then? If you still have the unit, there something you should perhaps test. These units are all the same, with different labels printed on them and they all "prefer" Source A. That the only reason I bought mine labelled as Generator and City Power (despite using it for solar)... simply because the City Power is labeled as Source A.

Try swapping your sources as per your example connection photo with Source A = Eskom and Source B = Inverter and see if that perhaps results in the functionality you are expect. I can tell your for certain that both my units follow the following logic when in Auto mode:

A present + B present = A selected
A present + B missing = A selected
A missing + B present = B selected
 

In my case (with solar connector to B at the bottom and eskom connected to A at the top) the unit wants to stay in position A. When eskom fails, it jumps to B and the moment Eskom returns, it will go back to A. 

 

This is how it should function. Your grid is seen as the master and if present it will always use it. As you indicated inverter is just for the period without grid. This is based on auto. Manual is self explanatory.

Just a question, if you import circuit breakers and these devices etc. Will it not have an impact on your insurance if your put in a claim for any sort of electronic related issue like a lightning strike or fire? Don't they have to be SABS approved or whatever the SA electric board is called? Thanks 

3 minutes ago, McAllstar said:

Just a question, if you import circuit breakers and these devices etc. Will it not have an impact on your insurance if your put in a claim for any sort of electronic related issue like a lightning strike or fire? Don't they have to be SABS approved or whatever the SA electric board is called? Thanks 

Also wondered about that, but I did notice that almost none of my Schneider and Hagar breakers have SABS logos on them. And I definitely trust them way more than the MES rubbish I had in before which did have the SABS logo. I did notice that all my breakers have EN60947 certification (google says BS EN 60947-6-1 - Low-Voltage Switchgear and Controlgear). 

I don't know if we have a local equivalent of such a certification, but then again, having a SABS brand on something nowadays means it'll likely catch fire upon first use. Ultimately, I think the insurance companies only look for an electrical CoC being in place. 

10 minutes ago, McAllstar said:

Just a question, if you import circuit breakers and these devices etc. Will it not have an impact on your insurance if your put in a claim for any sort of electronic related issue like a lightning strike or fire? Don't they have to be SABS approved or whatever the SA electric board is called? Thanks 

Ah update... did a quick google search. There IS a South African standard (VC8036 / SANS-556-1 Lowvoltage switchgear Part 1: Circuit-breakers) BUT the regulator published an amendment stating that: 

Quote

EQUIVALENCE OF STANDARDS Standards issued by different standardization bodies such as ISO and EN, will only be accepted if it is proven, in the form of a declaration report from an accredited conformity assessment body, that they are technically equivalent to the relevant South African National Standard. The applicant shall be responsible for obtaining such a declaration report. Proof of conformity with such a standard shall be accepted as conformity with the corresponding South African National Standard

So it seems that as long as you have ISO or EN certification on your switchgear, SABS compliance is implied and the insurance man can't deny your claim based on that.

1 hour ago, recre8 said:

Ah update... did a quick google search. There IS a South African standard (VC8036 / SANS-556-1 Lowvoltage switchgear Part 1: Circuit-breakers) BUT the regulator published an amendment stating that: 

So it seems that as long as you have ISO or EN certification on your switchgear, SABS compliance is implied and the insurance man can't deny your claim based on that.

ah ok, that's excellent news. thanks for that. Surely most products will have that anyway as they also have regulations and standards in their own countries. Although I've seen some dodgy looking imported stuff. 

I have a TOMZN Ewelink Single Phase WIFI Smart Energy Meter Kwh Metering Monitoring Circuit Breaker Timer Relay for Smart Home 63A, that is rated at 63A. 

What are your thoughts on the rating? Would it handle 63Amp without issues? I was thinking of putting this in just after my Main Switch? Basically all the power of a house would go through this device? I want to do it to monitor my power usage.

14 minutes ago, McGuywer said:

I have a TOMZN Ewelink Single Phase WIFI Smart Energy Meter Kwh Metering Monitoring Circuit Breaker Timer Relay for Smart Home 63A, that is rated at 63A. 

What are your thoughts on the rating? Would it handle 63Amp without issues? I was thinking of putting this in just after my Main Switch? Basically all the power of a house would go through this device? I want to do it to monitor my power usage.

I wouldn't necessarily trust it to run at 63A continuously, but with the normal fluctuating power load of a house I don't see any problem. Best is to install it the way you want and monitor the temperature (by feel) when you know heavy loads are being pulled, e.g. tumble dryer together with kettle and geyser on etc. How often have you tripped your mains breaker?

Edited May 3, 20233 yr by recre8

13 minutes ago, recre8 said:

I wouldn't necessarily trust it to run at 63A continuously, but with the normal fluctuating power load of a house I don't see any problem. Best is to install it the way you want and monitor the temperature (by feel) when you know heavy loads are being pulled, e.g. tumble dryer together with kettle and geyser on etc. How often have you tripped your mains breaker?

I haven't tripped my mains in ages.

At the moment, I have a Tomzn 63Amp connected to a flat. I have seen a spike of just over 5000w once. I have not touched it to feel if it gets hot. 

I was thinking this is a good device to allow me to monitor my usage hourly.