Diesel Gen Set Start Up After A Year

[RichCor]

<...>

Now going to have to go back and think about the load for the deisel again.

The chageover switch is wired from the genset to supply one phase of the house. This is the black phase.

On that phase are: kitchen lights, main bedroom lights, house rear lights plus LED spot, plugs outside rear house, plugs laundry room, plugs kitchen, and a Daikin RM24NV2S inverter air conditioner.

All the house lights are LED, there is usually nothing on the outside plugs, laundry room, and only an ocassional microwave on in the kitchen. The air con uses about 8 to 9 A according to the meter on the AVR.

I read somewhere, again a while ago, that you should load a diesel at about 90%. If my deisel is rated at 5 KVA, 5KW, 22.7 A, then if I go on the number of Amps for 90% load that would be = 20 A.

90% is the MAX LOAD your GenSet should be designed to ever see (10% reserved overhead so nothing gets starved for current).

The maintenance run load rates generally run 35-50% of GenSet capacity.

1. Start and run the engine-generator monthly. Operate the engine until its temperature has been stable for at least 10 minutes. That’s when engine parts become lubricated, oxidation is prevented, old fuel is consumed, and overall functionality is verified.

   Operate the generator annually for a minimum of 1 hour at 100% of the generator nameplate capacity.

2. ...recommend minimum 35% to 40% rated load to avoid "wet stacking". Wet stacking occurs in a diesel engine when the engine is run at too light of a load during the run-in (also known as load banking). This causes unburnt fuel and oil to collect in the exhaust stack. The exhaust stack will be coated with a black, sticky, tar-like substance. If you run a new unit at light loads and/or idle for too long, the rings will not seat properly. If it is a diesel, wet stacking may occur. Both of these conditions will cause poor engine life and performance.

<...>

So I really need to feed another phase as well as the black phase at the output of my changeover switch, or maybe the whole 3 phases?

The pumps are on another circuit which is isolated from the house so that I don't get false SafeTCut trips. (as advised in another thread).

I have 3 inverter air cons, each on a different phase, and they draw: 8 A, 4 A, 4A.

Maybe I should wire the three phases to the output of the transfer switch, and for monthly testing only run the 3 air conditioners?

For emergency operation I could drop off one aircon?

I would switch off my 3 phase water heater before I transfered load.

I believe Crossy has his house wired this way off his GenSet.

Edited September 23, 2015 by RichCor

[Crossy]

I am assuming you have a 3-phase transfer switch - if not you cannot run multiple phases off your single-phase genset.

You need to link the phases at the genset input of the transfer switch (the connections will currently have nothing on them), do NOT that's NOT link phases anywhere else, this will result in a large bang!

As to the neutral current.

In a balanced 3-phase system (phase voltages 120^o apart) the neutral current will be the phasor-sum of the phase currents and will be zero (10+10+10=0). In a 3-phase system wired to a single phase source (phase voltages in-phase) the neutral current will be the arithmetic sum of the phase currents (10+10+10=30).

[carlyai]

I am assuming you have a 3-phase transfer switch - if not you cannot run multiple phases off your single-phase genset.

You need to link the phases at the genset input of the transfer switch (the connections will currently have nothing on them), do NOT that's NOT link phases anywhere else, this will result in a large bang!

As to the neutral current.

In a balanced 3-phase system (phase voltages 120^o apart) the neutral current will be the phasor-sum of the phase currents and will be zero (10+10+10=0). In a 3-phase system wired to a single phase source (phase voltages in-phase) the neutral current will be the arithmetic sum of the phase currents (10+10+10=30).

Don't want any of those 'bangs'.

I really appreciate the time you spend helping me and others out.

And thanks for reminding me about vectors.

I'll draw up that CaD diagram before I start things up.

Thanks again.

[carlyai]

<...>

Now going to have to go back and think about the load for the deisel again.

The chageover switch is wired from the genset to supply one phase of the house. This is the black phase.

On that phase are: kitchen lights, main bedroom lights, house rear lights plus LED spot, plugs outside rear house, plugs laundry room, plugs kitchen, and a Daikin RM24NV2S inverter air conditioner.

All the house lights are LED, there is usually nothing on the outside plugs, laundry room, and only an ocassional microwave on in the kitchen. The air con uses about 8 to 9 A according to the meter on the AVR.

I read somewhere, again a while ago, that you should load a diesel at about 90%. If my deisel is rated at 5 KVA, 5KW, 22.7 A, then if I go on the number of Amps for 90% load that would be = 20 A.

90% is the MAX LOAD your GenSet should be designed to ever see (10% reserved overhead so nothing gets starved for current).

The maintenance run load rates generally run 35-50% of GenSet capacity.

1. Start and run the engine-generator monthly. Operate the engine until its temperature has been stable for at least 10 minutes. That’s when engine parts become lubricated, oxidation is prevented, old fuel is consumed, and overall functionality is verified.

   Operate the generator annually for a minimum of 1 hour at 100% of the generator nameplate capacity.

2. ...recommend minimum 35% to 40% rated load to avoid "wet stacking". Wet stacking occurs in a diesel engine when the engine is run at too light of a load during the run-in (also known as load banking). This causes unburnt fuel and oil to collect in the exhaust stack. The exhaust stack will be coated with a black, sticky, tar-like substance. If you run a new unit at light loads and/or idle for too long, the rings will not seat properly. If it is a diesel, wet stacking may occur. Both of these conditions will cause poor engine life and performance.

<...>

So I really need to feed another phase as well as the black phase at the output of my changeover switch, or maybe the whole 3 phases?

The pumps are on another circuit which is isolated from the house so that I don't get false SafeTCut trips. (as advised in another thread).

I have 3 inverter air cons, each on a different phase, and they draw: 8 A, 4 A, 4A.

Maybe I should wire the three phases to the output of the transfer switch, and for monthly testing only run the 3 air conditioners?

For emergency operation I could drop off one aircon?

I would switch off my 3 phase water heater before I transfered load.

I believe Crossy has his house wired this way off his GenSet.

Hi Rich

Thanks again.

[carlyai]

I am assuming you have a 3-phase transfer switch - if not you cannot run multiple phases off your single-phase genset.

You need to link the phases at the genset input of the transfer switch (the connections will currently have nothing on them), do NOT that's NOT link phases anywhere else, this will result in a large bang!

As to the neutral current.

In a balanced 3-phase system (phase voltages 120^o apart) the neutral current will be the phasor-sum of the phase currents and will be zero (10+10+10=0). In a 3-phase system wired to a single phase source (phase voltages in-phase) the neutral current will be the arithmetic sum of the phase currents (10+10+10=30).

Don't want any of those 'bangs'.

I really appreciate the time you spend helping me and others out.

And thanks for reminding me about vectors.

I'll draw up that CaD diagram before I start things up.

Thanks again.

I have enclosed some pics and a drawing.

The first pic is the way the transfer switch is presently wired.

The next drawing (sorry haven't used TinyCad at the moment), is the way I propose to wire the transfer switch.

The next pic is the transfer switch technical details.

TransferSwitchPamphlet.pdf

Any need for concern regarding 'big bangs'?

Any other advice?

I think all the un-helpful sightseers are waiting for the big bang.

[Crossy]

Yes, that will work.

You could consider using two phases to at least perform some automagic load shedding when the genset starts.

Is your genset key start (but not automatic)? Have a look at this thread http://www.thaivisa.com/forum/topic/671221-build-a-low-cost-semi-automatic-generator-transfer-switch/ a little project to stop you having to go out in the rain (read the later part of the tread discussing the auto-start mods)

[carlyai]

Yes, that will work.

You could consider using two phases to at least perform some automagic load shedding when the genset starts.

Is your genset key start (but not automatic)? Have a look at this thread http://www.thaivisa.com/forum/topic/671221-build-a-low-cost-semi-automatic-generator-transfer-switch/ a little project to stop you having to go out in the rain (read the later part of the tread discussing the auto-start mods)

The second paragraph.

I saw this article some time ago and bookmarked it. So thanks again, but have it and have read it several times. Will get back to it.

First paragraph.

Don't quite understand this.

When I start the genset it will have no load for (have to reread the articles, but between 5 and 10 mins) to let it warm up.

Naah, don't understand this, "You could consider using two phases to at least perform some automagic load shedding when the genset starts."

'Load shedding', taking load off, isn't one reason I'm connecting all phases to the transfer switch so that the diesel will have more load?

I know you would have a good reason for what you've written but, sorry, just can't see it at the moment.

You are sooo right about that horrible insulation tape getting all wet and dribbly. I only put it on the cables to show the colours. Think I'll just take it off. Horrible stuff.

Was up in Mukdahan a few weeks ago and looking across the street from the restaurant I thought I saw a bare mains cable clamp, recognised it from ones I used on the SafeTCut. It was a street lighting cable and the connector was just above head height on the sidewalk. The insulation had peeled off the connector and left a large bare live cable.

[Crossy]

Carl. You need to limit your load to within what the genset can provide (of course you know that).

I understood that was your reasoning when you used a single phase with all the essentials on it.

If you now have all 3-phases available to the genset you will have to manually limit (shed) the load to avoid frying the genset.

You could meet in the middle and use 2 of the phases.

EDIT If the idea is to be able to provide for 100% of genset load occasionally for testing etc. then why not make the links switchable so you don't have to think too much in the dark and pouring rain.

[carlyai]

Carl. You need to limit your load to within what the genset can provide (of course you know that).

I understood that was your reasoning when you used a single phase with all the essentials on it.

If you now have all 3-phases available to the genset you will have to manually limit (shed) the load to avoid frying the genset.

You could meet in the middle and use 2 of the phases.

EDIT If the idea is to be able to provide for 100% of genset load occasionally for testing etc. then why not make the links switchable so you don't have to think too much in the dark and pouring rain.

Yeah you're right Crossy.

I was planning on load shedding, but I was thinking you meant shedding the load as the diesel was running, while I would have the load shed before I started the diesel. Just my wrong thinking.

I was planning to leave the water heaters off, there's 18 A running ( 8-9 A each according to the AVR)and > 50 A starting according to the AVR. Also not use the microwave.

The pumps are run off the incoming mains taken through under/over voltage protection and the first CU, so no load on the generator.

The main load on the gen. will be the three air conditioners, 8 A, 4 A and 4 A =16 A.

The other loads will be the 2 TV's, fridge, fans, and LED lights. No toaster etc and gas cookers.

So I was thinking that I would probably need the 3 phases on to get enough load of around 20 A.

I wasn't too keen on connecting the water heaters as the heater elements must be near short cct when current is applied as the amp meter on the AVR flicks past 50 A for a poofdeenth of a second, but not sure of this effect on the gen set turning hot water taps on and off, better to leave it off, thought I.

Think I'll wire up the 3 phases to get the aircon loads, and just see what the Gen Amp meter shows.

Then run the diesel for an hour under load.

And then have another think.

Thanks again.

[carlyai]

Looking again at the gen set I noticed it only has a volt meter and not an amp meter.

I'll have to install some amp meters on my changeover switch, one of these days, soon.

Now that I cannot monitor how much current the load is drawing, I went for the one phase connected only.

This should be about 10 or more amps.

Diesel started OK, and before I started it I turned it over several times without starting to oil the bores, as suggested.

Ran it for 5 min no load and then on load for 1 hour, then 5 min no load.

Walked down the road and you can hardly hear anything in the neibours places, though the policeman behind was cleaning his semi-automatic when I walked in, but he smiled, so must have not been too noisy.

Got some pics, but don't know if I can attach movie clips here, will try. Looks like you can't, no worries.

Thanks again all who helped me again.

[Crossy]

During our occasional extended outages the neighbours turn up to watch our TV, use our internet (fibre) and drink my beer

Maybe time to lose the genset.

If you want to insert movies into a post, upload them to Youtube first.

[carlyai]

During our occasional extended outages the neighbours turn up to watch our TV, use our internet (fibre) and drink my beer

Maybe time to lose the genset.

If you want to insert movies into a post, upload them to Youtube first.

Funny you should mention that.

Yesterday while looking around out the back I had visions of extension leads disappearing over the back fence during an outage.

[carlyai]

Talking now about Amp meters.

Just some old fashion analogue amp meters in series with the output from the transfer switch?

There are digital Amp and Volt meters combined with electronic cct. maybe use them?

What do you think?

[Crossy]

I'm using one of these http://www.ebay.co.uk/itm/Digital-AC-100-300V-50A-Blue-LCD-Amp-Volt-Ammeter-voltage-Panel-Meter-gauges-/231046353676?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item35cb6f930c works like a charm.

You can see it installed in this post http://www.thaivisa.com/forum/topic/671221-build-a-low-cost-semi-automatic-generator-transfer-switch/?p=8142666

[carlyai]

Thanks again.

Amp/Volt meter in link pic seems to have only one connector.

Can't find a cct on the internet.

Do you think my cable size wiring from the transfer switch will fit into those screw terminals, or am i going to have to modify my wiring?

Beautiful steady rain here.

Hope you are not flooded again.

Edited October 8, 2015 by carlyai

[Crossy]

We're fine on the flooding front thanks, we don't suffer flash floods during the storms but we are very close to the river so we get the 'slow motion train wreck' type flooding.

We've not actually had water in the house since 2011 (whilst we were still building). We do however have the correct postcode for local government flood relief (food, torches, batteries, sandbags) which Wifey dutifully collects and distributes to other villagers who are less fortunate than us.

EDIT. You connect two (thin) wires from the green connector on the meter to the 220V from your genset, that powers the meter and it measures the voltage. You feed one (fat) wire from your genset through the current transformer (the round black thing) on its way to the load to sense the current. Look at the photos I linked to earlier and you can see the (in this case white) going through the CT. You may have to splice in a bit of thinner wire to fit through the hole.

A closer photo of it connected up, ours has a small white connector instead of the green one, same wiring. The rightmost two connections on the big terminal strip go to the genset, the two immediately to their left go to the house. You can feed either L or N (but not both) through the CT.

[carlyai]

We're fine on the flooding front thanks, we don't suffer flash floods during the storms but we are very close to the river so we get the 'slow motion train wreck' type flooding.

We've not actually had water in the house since 2011 (whilst we were still building). We do however have the correct postcode for local government flood relief (food, torches, batteries, sandbags) which Wifey dutifully collects and distributes to other villagers who are less fortunate than us.

EDIT. You connect two (thin) wires from the green connector on the meter to the 220V from your genset, that powers the meter and it measures the voltage. You feed one (fat) wire from your genset through the current transformer (the round black thing) on its way to the load to sense the current. Look at the photos I linked to earlier and you can see the (in this case white) going through the CT. You may have to splice in a bit of thinner wire to fit through the hole.

$_57.JPG

A closer photo of it connected up, ours has a small white connector instead of the green one, same wiring. The rightmost two connections on the big terminal strip go to the genset, the two immediately to their left go to the house. You can feed either L or N (but not both) through the CT.

meter.jpg

That's brilliant!

I was thinking of 3 meters, on phases.

Thanks again, no notification of your reply sent to me, maybe when you edit it doesn't send a notification as it's in the same post.