Is it bad practice to run the engine whilst on EHU (1 Viewer)

[Jewellbags]

Just double checking but my dealer said that you should t really run the engine whilst on EHU ... thoughts folks ?

 

[Viennese]

I don't understand why you would want to do it. It's now potentially an offence to run an engine while stationary - the emissions from idling engines are greater than when the vehicle is moving.

 

[Pikeman]

Im going to add to the growing voice shouting 'why' ?

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[Spriddler]

It's now potentially an offence to run an engine while stationary -

So that's the end of a Mr Whippy on the prom.

 

[Pausim]

So that's the end of a Mr Whippy on the prom.

Shouldn’t that sort of thing happen in private?

 

[eddie]

Of course I could be talking out of my exhaust pipe.

Never !

But! There is no reason fundamentally why starting the engine would be an issue, pointless for most people? probably. Dangerous? only because people will drive off with the van plugged in and cause damage.

One of our customers got quiet upset when we invoiced him for over £400 for a replacement hook up bollard! He had, to avoid a coil, loosely draped his 25m hook up cable round and round our bollard, which houses dusk to dawn lights and sensors, two water points and an additional hook up. Drove off at a rate of knots, with our bollard bouncing and dancing behind his motorhome!

Couldn't understand why we expected him to pay for a replacement, even though we had pointed out that the £400 was what we paid and that we were not charging for the labour to install it!

But, back to the point in question. On RV's the built in generators are designed to run the house Air Conditioning on the move. In June we were returning to the UK in the French heat wave and we drove over four hundred miles with the outside temperature over 40°c the camper was lovely and cool with the combination of ducted roof A/C and dash A/C with the advantage of the fact that as we had mains, we used a 14" 220V floor standing "fan" pointing at Shadow's (our dog) bed so he was very comfortable to.

Our Victron inverter/charger has something called shore assist and will, when on hook up, change from being a charger to being an inverter should the demand outstrip the supply, simple terms, 6 amp hook up available, and the hairdryer needs 12 amp the Victron will "make up" the missing 6amps to avoid tripping the mains supply or wet hair (a fate worse than death apparently) it automatically detects when mains is available and uses it, and automatically detects when there is no mains available, so starting the engine when plugged into the mains is no different to starting the generator when driving.

I suspect that people are told not to, as it is easier. Often people will ask me a question and I will answer negatively as I don't wish to start an argument, nor do I wish to risk being roasted on Social Media. I'll give you an example, if we (Van Bitz) were asked "Should I disconnect an engine battery before charging with a portable mains battery charger" I would answer "Yes!"

But, If I was asked "if you were charging your battery with a battery charger would YOU bother to disconnect, the answer would be "no"

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[gus-lopez]

I don't understand why you would want to do it. It's now potentially an offence to run an engine while stationary - the emissions from idling engines are greater than when the vehicle is moving.

I do it at home as the van is permanently plugged in & if I am adding bits/working on it at times it is necessary to start it. Sometimes I need to run it up the ramps but I never bother unhooking.

 

[Blueskybobster]

Why not?

I would ask why would you want to?
Apart from the noxious fumes you're enveloping the van and surrounding area, what are you trying to achieve.

 

[minesapint]

I was under the impression that if you run the engine whilst Hooked up...It can have a undesirable effect on the charger? Pappajohn...Do most motorhomes have that link you mention?
I have done it to be honest , but been told off by the dealer when mentioning it? Dont know why ...even now? Interested to know the correct way..

With my Hobby Van, I must not run the engine with the EHU hooked up. If I do it blows the fuse in the Sargent charger. Then its a right pain to put in a new one. Drivers seat off to change it.

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[eddie]

With my Hobby Van, I must not run the engine with the EHU hooked up. If I do it blows the fuse in the Sargent charger. Then its a right pain to put in a new one. Drivers seat off to change it.

That sounds like there is another issue. What fuse do you replace? a mains fuse or a 12 volt fuse?

Your AC side should have nothing to do with your DC side except battery charging, and as has been explained, charging a battery from two sources isn't an issue, Solar when on hook up for example of a Fuel Cell and Solar and Alternator when driving

 

[two]

Im going to add to the growing voice shouting 'why' ?

Why what?
- want to run the engine while on EHU?
- might it be damaging to do so?

It's not unreasonable advice to give, but relatively unimportant in my view.
I can't see any harm being done by running the engine whilst on EHU, although it might confuse some 'smart' chargers that see a higher voltage than they'd expect to see and react strangely.
I'm sure it's been done, often. If it caused serious problems, we'd have heard about it many times over by now.

 

[Euro330]

Unless I am mistaken, my, and other Bailey`s automatically switch control panel off so you are charging batts on alternator, you only have to switch fridge over from mains to vehicle charging.
Could be completely wrong, then again I believe we should banish the monarchy so what do I know!

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[The Dotties]

The warning buzzer on my Sargent panel would do my head in!

 

[yodeli]

As asked elsewhere, why do you want to run it.?

I do, because in winter, the engine might not like staying too long without a now and then start and run. I do it every 2 or 3 days at the moment as it's quite cold here, but it stays in front of my house, as I also run electric heater during the day and before you ask, no , not during the night, as I've had already rats in and I know they love comfy mohos! During the day I dry it up. I leave a little square of sponge on the table to see if the damp has been imortant during the night.

 

[Richard n Ann]

I do, because in winter, the engine might not like staying too long without a now and then start and run. I do it every 2 or 3 days at the moment as it's quite cold here, but it stays in front of my house, as I also run electric heater during the day and before you ask, no , not during the night, as I've had already rats in and I know they love comfy mohos! During the day I dry it up. I leave a little square of sponge on the table to see if the damp has been imortant during the night.

Our engine hasn't run since September. And probably won't run it until March. Same every year and it's fine ?

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[Spriddler]

Our engine hasn't run since September. And probably won't run it until March. Same every year and it's fine ?

Brighton Corporation's 20 or so gritters last for many years and are only used for a few weeks a year. They're just parked up outdoors on chargers until needed.

 

[HandyAndy]

Its impossible for a dc "alternator" to do any damage to an on board 12v or 240v circuit when the engine is started.
If it was an issue and you had solar panels, as soon as the sun came out, you'd have the same issue as it's exactly the same thing in terms of electricity delivery that happens then as it does when you start the vehicle.
DC amps at circa 14.4v travels to all your circuits from both alternator and solar in exactly the same way.

On the subject of inverters, there is absolutely no way an on board inverter would be wired to the existing 240v circuitry without either a manual or automatic changeover switch installed.
So the comments about maybe its because an inverter automatically switches on is tosh.

You have to do this because the EHU AC sine wave may not be in sync with the inverter sine wave and there would be a big bang if two AC sources were brought together at the wrong time. This would happen if you switched the inverter on manually or switched it on with the engine running, its no different.
Posh inverters like the victron, sense the EHU sine wave and adjusts it's own sine wave to match before It allows the latching of a relay and allowing the two AC sources to join forces. Then as eddievanbitz said, it can do funky stuff like power assist as well.

 

[yodeli]

Our engine hasn't run since September. And probably won't run it until March. Same every year and it's fine ?

Max is an old man of 1991 . Probably makes the difference. In any case, don't want to take the risk of failing a start. I work 7/7 and getting an appointement is just hell to me. Then , going to the mechanic is alright , and then ? Coming back is another joke! No one here to help , no one at all. Having to rely on me only is also the point.

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[Phill D]

That’s to stop people driving off plugged in

yes i though i'd said that...
but not as directly as well put as you......" to warn the cable is still attached!!!"

 

[wotme]

I'll tell you why I run the engine whilst hooked up. I do it quite often because I'm not strong enough to push the van out of the way when I need to get in my garage and I also think it wise to re-distribute the weight on the tyres every month or so

 

[GWAYGWAY]

IF you have lion batteries then you SHOULD NOT run the engine at tickover for any protracted time at all, Alternators are not that efficient in power to electricity and will convert half the output to heat, with li on batteries this is very high as they will accept everything the alternator can give, lead batteries will progressively resist in incoming current and are therefore self regulating.
The alternator at tick-over is not cooled enough by the slow running fan but a normal running speed is cooled OK. Unless there is a heat sensor governor in the alternator it will overheat to Actually burning out completely.

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[thebriars]

I can't see any harm being done by running the engine whilst on EHU,

Depends how often and for how long, and how new the motorhome is. Nothing to do with the EHU connection, BUT a modern diesel does not like being frequently started and left on tickover. A great way to block the DPF and end up with the engine going into limp home mode, and then a tow to the garage to get it sorted.

 

[CazPaul]

I found this information online by the late Alan of aandncaracavanservices. I took out names and put initials in.

Quote
''There you go, S starting and reversing his vehicle is proof the Elektroblock has the protection against accidental damage.

However, we certainly DON'T advocate anyone doing this, as the majority of Motorhomes will not survive unscathed, exactly as we point out at the beginning of our response.
In a worst case there could be melted Sargent boxes and all sorts.

Hence saying, " How much damage is done to the wiring/relays will depend on the current that follows. How much damage is done to the mains charger will depend on what protection is built in. There are hundreds of chargers working in different ways".

Our response it 'was safe to do', as J points out above, was specifically for a question on the Elektroblock EBL 99 and even then we said there were risks (even highlighting a charger we removed that was burnt out) if things were not ideal.

So to be absolutely clear, we don't advise anyone starts the engine while on EHU.

The EBL 99 has protection built in, that should protect it IF the Motorhome electrics are in perfect condition. If any of the things listed in the response, like a poor battery, etc, even an EBL 99 is likely to suffer.

Hence us saying it is safer not to.''

 

[Captain Lloyd]

I have a Rapido 8094df the manual says, doesn’t say why though

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[joka250]

If I run ours with Comfortmatic on idle on EHU or not in neutral a continuous loud warning sounds, drives you mad.

 

[Pausim]

If I run ours with Comfortmatic on idle on EHU or not in neutral a continuous loud warning sounds, drives you mad.

Ours does that until I move the gear selector up to the neutral position.

 

[minesapint]

That sounds like there is another issue. What fuse do you replace? a mains fuse or a 12 volt fuse?

Your AC side should have nothing to do with your DC side except battery charging, and as has been explained, charging a battery from two sources isn't an issue, Solar when on hook up for example of a Fuel Cell and Solar and Alternator when driving

Hi the Sargent charging system has an inbuilt fuse which will blow if you start the engine on hook up. Seems logical why would you want to start your engine with the EHU in place. The book says do not do it so I do not. Simples.

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[eddie]

The book may say not to do it, but then Sargent systems don’t even allow you to flush the loo when the engine is running rather than get EMC testing done like every other system used on every other European motorhome

Doesn’t explain how it creates a short circuit and blows a fuse

 

[Pausim]

Perhaps it is time for Sargent to design equipment suitable for motorhome use rather than using a caravan system where starting engines and wanting to use 12V electrics seems to cause conflicts.

 

[SpeedyDux]

I would never run the engine while on EHU - it wouldn't occur to me to do this. It's a waste of expensive diesel. As has been said the Euro6 spec engine will clog the DPF quicker, and heaven knows what long-term adverse effect prolonged idling has on the EGR system and various sensors.

Overall this thread shows the difference between unfortunate examples of "is" (as in, my experience was that this caused expensive or annoying problems) and "ought" (all should be well, nothing to worry about).

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[Jim]

I often run my van to use the B2B to crash charge my Lithium. I don't worry about it though, my van is superior to many European engines in this regard, in as much as the makers know that many times trucks/van need to idle, especially ambulances, which is why the ambulance mode when enabled allows the engine to idle for extended periods. Essentially, it monitors what is going on and will after a while increase/decrease/increase revs to protect the DPF and EGR systems etc.