Build a low cost semi-automatic generator transfer switch.

[Crossy]

Latest Update.

I've replaced the big relay with a 4-pole contactor (2-NO, 2-NC), this one http://www.ebay.com/itm/261858824296?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Again, I've used that Ebay seller several times and they've proven reliable and competitively priced, they're on AliExpress too if that's your poison.

Why? I noticed some sparking on the relay contacts when it changed over on load, nothing to worry about but these contactors look pretty good and are well priced.

Diagram of how to wire it up as a direct replacement for the relay coming soon.

I'm also doing automatic load-shedding when the genset starts so I can run one aircon but isolate the water heaters and other non-vital circuits so I don't fry the beast accidentally.

It's simple really, diagram to follow when I've drawn it

[Crossy]

OK the diagram

This will provide;-

1. Auto-start of the genset on mains fail.
2. Under / over volt protection (power off) of all kit even if the genset isn't running (out of fuel, off coz it's night etc.).
3. Shedding of non-essential loads (like water heaters) when the genset is running to prevent overload.

[Crossy]

I noticed that the ATS contactor was buzzing for a second or two as the genset came up to speed before clunking over and transferring the power. Evidently the genset output does not come up to voltage instantly.

I doubt there's a serious issue as in normal use the mains is off (so no current flowing) when the beast changes over but testing with mains on could lead to arcing if the contacts chatter.

The genset controller I have does not have an output-enable function to operate a genset output contactor so I shoehorned an under / over unit into the box with the controller, this then ensures the voltage is in range before connecting the genset to the load.

This is the unit I used (happened to be 'in-stock' in my bits box) http://www.ebay.com/itm/261903753257?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Mine takes about 15 seconds to turn on once the genset is up to speed. The same seller do an adjustable one which could be used if you don't want to wait for the (somewhat broad) fixed time.

Here it is levered into the box with the controller, any more smart ideas and I'm going to need a bigger boat box.

[getout]

I posted earlier in this thread when I first started looking at using my existing petrol generator as a backup power source. I have since spent time learning electronics and electrical wiring fundamentals before deciding to design an ATS for use with a new diesel generator already equipped with a 2 wire auto start function. This way I don't need to worry about using an old and ill-equipped generator as my backup power source.

I don't have any design software to simply draw a diagram so I thought I would explain with an image of the hardware I've collected. Please let me know if I've made a mistake in my thinking:

 

From left to right:

Left Power Meter to record details of Mains input power consumption

Circuit 1 RCBO 20 amp

Circuit 2 RCBO 16 amp

4 pole contactor 63 amp to switch mains and geni power

2 pole contactor 40 amp for triggering the Genset and controlling Geni Active output

Right Power Meter to record details of Geni input power consumption

Over/Under regulator to provide a clean 240v from geni

 

Firstly the Active wire from the Mains will be connect through the Power Meter on the left. The Geni will firstly have its Active and Neutral running through the Over/Under regulator (maybe this could be incorporated elsewhere but I just thought to put it before any other components) then the Active wire will be run through the Power meter on the right. Then onto the 63amp contactor inputs.

 

Mains Active and Neutral will be connected to R1 & R3 (NC) of the 63amp contactor.

 

Geni Active and Neutral will be connected to 1 & 3 (NO) of the 63amp contactor.

 

The 63amp contactors corresponding Active outputs R2 & 2 will be jumpered together along with the corresponding Neutral outputs R4 & 4 and so a single Active and Neutral can be wired to the first RCBO (and jumpered to the next RCBO).

 

The Mains Active on R1 63amp contactor will be jumpered to the coil's A1 of the 40amp contactor and the Mains Neutral on R3 63amp contactor will be jumpered to the coil's A2 of the 40amp contactor (keeping the 40amp contactor's NC R1 - R4 connections open while Mains power is on).

 

The Geni Active on 1 63amp contactor will be jumpered to R3 40amp contactor, the output of which R4 will connect to the coil of the 63amp contactor A1 (corresponding A2 will be jumpered to the Geni Neutral on 3 63amp contactor). This will control the switching of the 63amp contactor to Geni power once the mains fails and the geni is started.

 

R1 and R2 will have the Auto Start wire of the Genset connected, once mains fails the coil of the 40amp contactor denergizes and its contacts close completing the circuit for the Genset setting off the whole process.

 

How does this sound?.......

 

 

 

 

 

[Crossy]

@getout

 

You'll need some means to actually open the 40A contactor on mains low, what you have will work fine if the mains goes OFF but the contactor will remain energised well below 160V on the mains (at which point you really want to be on generator), see my comments earlier in the thread about using a relay as a mains sensor, basically it doesn't work well.

 

You could use the over/under you already have, re-purpose (or use another) to monitor the incoming supply and open the contactor when the supply is over or under as well as actually off.

 

[getout]

39 minutes ago, Crossy said:

You could use the over/under you already have, re-purpose (or use another) to monitor the incoming supply and open the contactor when the supply is over or under as well as actually off.

 

Hi Crossy,

thanks for the quick reply. I can order another over/under device, I have the extra space on the DIN rail you can see in the image. Would you suggest wiring the over/under as the first device connected to mains and geni power (before the power meter)?

[Crossy]

The over/under that controls the contactor needs to monitor the incoming mains so the contactor opens when the power goes off/low. If you look at my drawings earlier in the thread you should be able to follow what's needed.

 

I would draw up what you intend doing and post it here, even a paper sketch imaged with your phone would be fine. You'll need a diagram to build it anyway, trying to do it on the fly makes life very difficult when working out why it doesn't behave as expected.

 

My drawings are done with TinyCAD a free electrical / electronic CAD package. https://sourceforge.net/projects/tinycad/

 

[Crossy]

Whilst looking for something else I came across this generator controller:-

 

http://www.gencontrol.co.uk/auto-start-for-hyundai-genset.html

 

It can hook directly onto the ignition switch of most key-start generators without a load of extra salad-dressing. Not cheap, but in terms of mucking about, unbeatable.

 

The manual Key-switch-replacement.pdf

 

[crs]

So a HYUNDAI HD-6500 LDE (http://www.hyundaipower-th.com/product/pro_detail.php?cid=2&cid_pr=2&pid=10&cname=เครื่องกำเนิดไฟฟ้า ดีเซล&show=0) + one of these controllers = a fully automatic standby generator? Is that about the cheapest option I've got for a low demand (few PCs) setup, Crossy?

[Crossy]

2 hours ago, crs said:

So a HYUNDAI HD-6500 LDE ...

Let me check the spec. of that little genset, you need something that is key start and (important) key stop.

 

[crs]

Yeh, can't find spec for that model in En. If you know of any other that'd suit then please tell but (as said in that other thread) I'd prefer PnP setup if not loads more quid. Cheers.

[Crossy]

4 minutes ago, crs said:

Yeh, can't find spec for that model in En.

Thai would be OK if you have a link ?

 

The ideal thing would be the manual (En or Th).

 

[crs]

Not seen a manual - only spec I can find is on that linked page. Will see if can find what looks like same/similar model with dif name on UK/US sites...

[crs]

Crossy, can't find a manual that is definitely for that Hyundai model - but, google translate does say ATS is optional...

 

https://translate.google.com/translate?sl=auto&tl=en&js=y&prev=_t&hl=en&ie=UTF-8&u=http%3A%2F%2Fwww.hyundaipower-th.com%2Fproduct%2Fpro_detail.php%3Fcid%3D2%26cid_pr%3D2%26pid%3D10%26cname%3Dเครื่องกำเนิดไฟฟ้า%20ดีเซล%26show%3D0&edit-text=

[Crossy]

I've certainly seen gensets around 5kVA with ATS connectors, don't recall where or what they were but with the optional ATS you should be good to go although you may need extra hardware, depending upon exactly what the "ATS" consists of.

 

All you have to do now is find a supplier that will supply with the options.

 

By the way, 5kVA will run most homes if you exclude the water heaters, our 5kVA gasoline unit also runs our bedroom A/C.

 

[crs]

Thanks.

[Crossy]

Meanwhile I've replaced the Omron relay with a 220V one of these purely because it results in a neater appearance.

 

https://www.aliexpress.com/item/GEYA-GR8-AC230V-DC24V-Intermediate-Relay-Auxiliary-Relay-8A-16A-SPDT-Electronic-Relay/32881214888.html4fd4c4dzbMIW5

 

 

Also replace the neon with a DIN mount indicator, again for a neater "finished" look.

 

https://www.aliexpress.com/item/breaker-Indicator-C45D-DZ47-indicator-light-C45D-signal-lamp-red-yellow-green-good-quality/32674721518.html

 

 

[Esso49]

On 7/12/2018 at 11:16 AM, Crossy said:

I've certainly seen gensets around 5kVA with ATS connectors, don't recall where or what they were but with the optional ATS you should be good to go although you may need extra hardware, depending upon exactly what the "ATS" consists of.

 

All you have to do now is find a supplier that will supply with the options.

 

By the way, 5kVA will run most homes if you exclude the water heaters, our 5kVA gasoline unit also runs our bedroom A/C.

 

Yes they sell them in Global c/w ATS. 

[Crossy]

1 minute ago, Esso49 said:

Yes they sell them in Global c/w ATS. 

That's great news. Which Global did you see them in, stocked items seem to vary?

 

Do they offer an installation service?

 

[bankruatsteve]

4 hours ago, Crossy said:

Meanwhile I've replaced the Omron relay with a 220V one of these purely because it results in a neater appearance.

 

https://www.aliexpress.com/item/GEYA-GR8-AC230V-DC24V-Intermediate-Relay-Auxiliary-Relay-8A-16A-SPDT-Electronic-Relay/32881214888.html4fd4c4dzbMIW5

 

At the risk of being admonished for not referring to your diagrams, what does this thing do?

 

[Crossy]

Just now, bankruatsteve said:

At the risk of being admonished for not referring to your diagrams, what does this thing do?

It's just a neater version of the relay I used in the earlier designs.

 

It takes the single 220V switched signal from the under-over sensor and gives an isolated (volt free) output to the generator controller (to start the genset). It also switches the coil of the transfer contactor when the power returns and takes the load off the genset before stopping the beast.

 

See the earlier diagrams (it replaces the Omron relay).

 

[Esso49]

5 hours ago, Crossy said:

That's great news. Which Global did you see them in, stocked items seem to vary?

 

Do they offer an installation service?

 

They had identical stock in Udon Thani and Nong Khai stores. As for installation service I have no idea but there  again when I asked the staff how to wire it up they had no idea either.

[Crossy]

4 minutes ago, Esso49 said:

They had identical stock in Udon Thani and Nong Khai stores. As for installation service I have no idea but there  again when I asked the staff how to wire it up they had no idea either.

One would hope it comes with instructions ... or maybe not ?

 

[Esso49]

36 minutes ago, Crossy said:

One would hope it comes with instructions ... or maybe not ?

 

That was the problem. It had instructions for operating and maintain the gen set,  not how to wire up the ATS.

[Crossy]

5 minutes ago, Esso49 said:

That was the problem. It had instructions for operating and maintain the gen set,  not how to wire up the ATS.

Typical of course.

 

It's not exactly rocket science only 8 wires, but getting them wrong can lead to bangs ?

 

Mains in - L & N

Genset in - L & N

Supply out - L & N

Genset start - 2 wires, contact closed to start.

 

[ericnoodeeka]

14 minutes ago, Crossy said:

Typical of course.

 

It's not exactly rocket science only 8 wires, but getting them wrong can lead to bangs ?

 

Mains in - L & N

Genset in - L & N

Supply out - L & N

Genset start - 2 wires, contact closed to start.

 

u seem to know ur stuff crossy, what u think of this? these things any good?

 

[ericnoodeeka]

1 minute ago, ericnoodeeka said:

u seem to know ur stuff crossy, what u think of this? these things any good?

 

28 quid on ebay

[Crossy]

1 minute ago, ericnoodeeka said:

u seem to know ur stuff crossy, what u think of this? these things any good?

The problem I see with these is that they don't appear have a set of contacts to start the genset. You'll need to add some sort of mains monitor to trigger the genset to start when the mains is off.

 

[Crossy]

3 minutes ago, ericnoodeeka said:

28 quid on ebay

Start at about USD 25 on AliExpress.

 

[ericnoodeeka]

2 minutes ago, Crossy said:

The problem I see with these is that they don't appear have a set of contacts to start the genset. You'll need to add some sort of mains monitor to trigger the genset to start when the mains is off.

 

see what you mean, I watched a Scottish bloke reverse engineer one of these things and he said they were ok, cant remember how he solved the switching on of the genny though.i will try to find the video again and put a link up . looking myself for a genny set up, getting daily powercuts here in sakon, if you not too far could come over and you could give me sm advice.