Inverters and caravans.

  • Thread starter rg26ce1991@hotmail.com
  • Start date
R

rg26ce1991@hotmail.com

Guest
Greetings group.
I read in the current Altronics catalog (page 234) that inverters
should only be used for stand alone use.

They should not be connected directly to the fixed wiring in a caravan.

I expect the reason is something to do with safety, but what is the
reason?

Thanks,
Russell.
 
rg26ce1991@hotmail.com wrote:
Greetings group.
I read in the current Altronics catalog (page 234) that inverters
should only be used for stand alone use.

They should not be connected directly to the fixed wiring in a caravan.

I expect the reason is something to do with safety, but what is the
reason?
Click to expand...
Probably the phase difference between the voltage output by your
inverter and that of the mains should both be connected to your caravan
at the same time!
 
<rg26ce1991@hotmail.com
I read in the current Altronics catalog (page 234) that inverters
should only be used for stand alone use.
Click to expand...

** It's on page 243 actually.


They should not be connected directly to the fixed wiring in a caravan.

I expect the reason is something to do with safety, but what is the
reason?
Click to expand...

** In case some fuckwit connects up the regular 240 volt AC supply at the
same time.

Likely destroy the inverter whether on or off.



........ Phil
 
On 18 May 2006 16:20:05 -0700, "rg26ce1991@hotmail.com"
<rg26ce1991@hotmail.com> wrote:

Greetings group.
I read in the current Altronics catalog (page 234) that inverters
should only be used for stand alone use.

They should not be connected directly to the fixed wiring in a caravan.

I expect the reason is something to do with safety, but what is the
reason?

Thanks,
Russell.
Click to expand...

1> in case the mains gets connected as well, while the inverter is
connected. This would certainly blow the crap out of the inverter, and
probably blow the mains fuse as well.

(Its also remotely possible (depending on the design and isolation of
the inverter) that 240v could end up across the inverter's battery, If
this happened, the battery could even explode, spreading acid
everywhere.)


2> possible earthing issues. Since a caravan is electrically
insulated from terra firma, unlike a house which has its own earth
stake, I dont know what the proper procedure should be for caravan
earthing, when run off a generator or inverter - that likely isnt
earthed either.
 
1> in case the mains gets connected as well, while the inverter is
connected. This would certainly blow the crap out of the inverter, and
probably blow the mains fuse as well.

(Its also remotely possible (depending on the design and isolation of
the inverter) that 240v could end up across the inverter's battery, If
this happened, the battery could even explode, spreading acid
everywhere.)
Click to expand...
There have been several cases I know of where caravans fitted with inverters
have been hard wired to the 240 V reticulated wiring. Two of these cases
were on private properties where the owner did the installation themselves.
The inverters worked OK on the DC source but of course as soon as the vans
were hooked up to the house power - well one burned to the ground and the
other resulted in a non-fatal electric shock (no RCDs in the house wiring
and connected via extension cords through the kitchen and bedroom windows).

In another case the inverter was installed by an electrician (wired in
permanently) who then complained to the supplier when it blew itself to
pieces when the mains was connected (again to a non-RCD protected domestic
GPO). His letter to the supplier makes interesting reading as it
demonstrates the profound lack of knowledge on his part, and the lack of
foresight on behalf of the supplier/manufacturer in not warning about not
installing the device that way.

2> possible earthing issues. Since a caravan is electrically
insulated from terra firma, unlike a house which has its own earth
stake, I dont know what the proper procedure should be for caravan
earthing, when run off a generator or inverter - that likely isnt
earthed either.
Click to expand...
Usually there are 'earth' connections to the frame or metal enclosure of the
gen/inv itself. These don't function like the earth in a mains installation
as there is no MEN connection on the gen/inv output, the earth is for static
dissipation rather than safety.. The output of the generator or inverter is
floating, the earth pin on the output is connected to frame ground and is
safe enough (to a degree) with respect to faults to exposed metal of devices
connected to the output. It would require a double fault for a serious
hazard to arise (one fault in the gen/inv insulation system and one in the
appliance).

In addition to inverters there are a few cases involving camping generators
being similarly wired in permanently within motor homes and carvans. The
alternators in the smaller camping generaotrs burn very nicely on a 15A GPO
until either they melt open circuit or they short to frame, in which case
the RCD in the supply should cut in. We did this to one last month to show
an importer why they really should have a warning in the instructions.

My company has been investigating and advising importers about these issues
for at least two years. The problem being few of the importers have any
knowledge of mains power systems. They just see the product at a trade show
in China and sell it, with the consequences being dealt with as they arise
since they were never foreseen and planned for (proper instructions,
warnings, etc).
 
"Dave"
There have been several cases I know of where caravans fitted with
inverters
have been hard wired to the 240 V reticulated wiring. Two of these cases
were on private properties where the owner did the installation
themselves.
The inverters worked OK on the DC source but of course as soon as the vans
were hooked up to the house power - well one burned to the ground and the
other resulted in a non-fatal electric shock (no RCDs in the house wiring
and connected via extension cords through the kitchen and bedroom
windows).

In another case the inverter was installed by an electrician (wired in
permanently) who then complained to the supplier when it blew itself to
pieces when the mains was connected (again to a non-RCD protected domestic
GPO). His letter to the supplier makes interesting reading as it
demonstrates the profound lack of knowledge on his part, and the lack of
foresight on behalf of the supplier/manufacturer in not warning about not
installing the device that way.

2> possible earthing issues. Since a caravan is electrically
insulated from terra firma, unlike a house which has its own earth
stake, I dont know what the proper procedure should be for caravan
earthing, when run off a generator or inverter - that likely isnt
earthed either.

Usually there are 'earth' connections to the frame or metal enclosure of
the
gen/inv itself. These don't function like the earth in a mains
installation
as there is no MEN connection on the gen/inv output, the earth is for
static
dissipation rather than safety.. The output of the generator or inverter
is
floating, the earth pin on the output is connected to frame ground and is
safe enough (to a degree) with respect to faults to exposed metal of
devices
connected to the output. It would require a double fault for a serious
hazard to arise (one fault in the gen/inv insulation system and one in the
appliance).

In addition to inverters there are a few cases involving camping
generators
being similarly wired in permanently within motor homes and carvans. The
alternators in the smaller camping generaotrs burn very nicely on a 15A
GPO
until either they melt open circuit or they short to frame, in which case
the RCD in the supply should cut in. We did this to one last month to
show
an importer why they really should have a warning in the instructions.

My company has been investigating and advising importers about these
issues
for at least two years. The problem being few of the importers have any
knowledge of mains power systems. They just see the product at a trade
show
in China and sell it, with the consequences being dealt with as they arise
since they were never foreseen and planned for (proper instructions,
warnings, etc).
Click to expand...

** Would seem the message got through to Altronics at least.

That is a good sign.

Since it took 20 years for the same pimply faced * fuckwits* to figure out
what the codes "A" and "B" indicated on the pots they were selling everyone.





........ Phil
 
"Phil Allison" <philallison@tpg.com.au> wrote in message
news:4dbel6F19d9t5U1@individual.net...
"Dave"

There have been several cases I know of where caravans fitted with
inverters
have been hard wired to the 240 V reticulated wiring. Two of these cases
were on private properties where the owner did the installation
themselves.
The inverters worked OK on the DC source but of course as soon as the
vans
were hooked up to the house power - well one burned to the ground and the
other resulted in a non-fatal electric shock (no RCDs in the house wiring
and connected via extension cords through the kitchen and bedroom
windows).

In another case the inverter was installed by an electrician (wired in
permanently) who then complained to the supplier when it blew itself to
pieces when the mains was connected (again to a non-RCD protected
domestic
GPO). His letter to the supplier makes interesting reading as it
demonstrates the profound lack of knowledge on his part, and the lack of
foresight on behalf of the supplier/manufacturer in not warning about not
installing the device that way.

2> possible earthing issues. Since a caravan is electrically
insulated from terra firma, unlike a house which has its own earth
stake, I dont know what the proper procedure should be for caravan
earthing, when run off a generator or inverter - that likely isnt
earthed either.

Usually there are 'earth' connections to the frame or metal enclosure of
the
gen/inv itself. These don't function like the earth in a mains
installation
as there is no MEN connection on the gen/inv output, the earth is for
static
dissipation rather than safety.. The output of the generator or inverter
is
floating, the earth pin on the output is connected to frame ground and is
safe enough (to a degree) with respect to faults to exposed metal of
devices
connected to the output. It would require a double fault for a serious
hazard to arise (one fault in the gen/inv insulation system and one in
the
appliance).

In addition to inverters there are a few cases involving camping
generators
being similarly wired in permanently within motor homes and carvans. The
alternators in the smaller camping generaotrs burn very nicely on a 15A
GPO
until either they melt open circuit or they short to frame, in which case
the RCD in the supply should cut in. We did this to one last month to
show
an importer why they really should have a warning in the instructions.

My company has been investigating and advising importers about these
issues
for at least two years. The problem being few of the importers have any
knowledge of mains power systems. They just see the product at a trade
show
in China and sell it, with the consequences being dealt with as they
arise
since they were never foreseen and planned for (proper instructions,
warnings, etc).



** Would seem the message got through to Altronics at least.

That is a good sign.

Since it took 20 years for the same pimply faced * fuckwits* to figure
out what the codes "A" and "B" indicated on the pots they were selling
everyone.





....... Phil
Click to expand...
I read with intrest comments made to this post.
I do also use an inverter and a genny(not at the same time) to mains power
my caravan.
There is no possibillity for a second mains supply as I connect either to
the
20 amp socket input on the outside of the van.
The groups mention of the earth issue got me thinking......
What would be the best way tho earth the caravan frame?
If I use an earth stake how long and how deep should that be?
Mathew
 
"Mathew Tiede" <MatTiede@bigpond.com> wrote in message
news:sfqcg.8925$S7.7003@news-server.bigpond.net.au...
"Phil Allison" <philallison@tpg.com.au> wrote in message
news:4dbel6F19d9t5U1@individual.net...

"Dave"

There have been several cases I know of where caravans fitted with
inverters
have been hard wired to the 240 V reticulated wiring. Two of these
cases
were on private properties where the owner did the installation
themselves.
The inverters worked OK on the DC source but of course as soon as the
vans
were hooked up to the house power - well one burned to the ground and
the
other resulted in a non-fatal electric shock (no RCDs in the house
wiring
and connected via extension cords through the kitchen and bedroom
windows).

In another case the inverter was installed by an electrician (wired in
permanently) who then complained to the supplier when it blew itself to
pieces when the mains was connected (again to a non-RCD protected
domestic
GPO). His letter to the supplier makes interesting reading as it
demonstrates the profound lack of knowledge on his part, and the lack of
foresight on behalf of the supplier/manufacturer in not warning about
not
installing the device that way.

2> possible earthing issues. Since a caravan is electrically
insulated from terra firma, unlike a house which has its own earth
stake, I dont know what the proper procedure should be for caravan
earthing, when run off a generator or inverter - that likely isnt
earthed either.

Usually there are 'earth' connections to the frame or metal enclosure of
the
gen/inv itself. These don't function like the earth in a mains
installation
as there is no MEN connection on the gen/inv output, the earth is for
static
dissipation rather than safety.. The output of the generator or
inverter is
floating, the earth pin on the output is connected to frame ground and
is
safe enough (to a degree) with respect to faults to exposed metal of
devices
connected to the output. It would require a double fault for a serious
hazard to arise (one fault in the gen/inv insulation system and one in
the
appliance).

In addition to inverters there are a few cases involving camping
generators
being similarly wired in permanently within motor homes and carvans.
The
alternators in the smaller camping generaotrs burn very nicely on a 15A
GPO
until either they melt open circuit or they short to frame, in which
case
the RCD in the supply should cut in. We did this to one last month to
show
an importer why they really should have a warning in the instructions.

My company has been investigating and advising importers about these
issues
for at least two years. The problem being few of the importers have any
knowledge of mains power systems. They just see the product at a trade
show
in China and sell it, with the consequences being dealt with as they
arise
since they were never foreseen and planned for (proper instructions,
warnings, etc).



** Would seem the message got through to Altronics at least.

That is a good sign.

Since it took 20 years for the same pimply faced * fuckwits* to figure
out what the codes "A" and "B" indicated on the pots they were selling
everyone.





....... Phil


I read with intrest comments made to this post.
I do also use an inverter and a genny(not at the same time) to mains power
my caravan.
There is no possibillity for a second mains supply as I connect either to
the
20 amp socket input on the outside of the van.
The groups mention of the earth issue got me thinking......
What would be the best way tho earth the caravan frame?
If I use an earth stake how long and how deep should that be?
Mathew
Click to expand...
Earthing the metal body of the caravan is a good precautionary way of
reducing the possibility of electric shock due to an electrical fault.
The length and depth you bury the earth stake depends on a number of
factors, but mainly the conductivity of the surrounding soil. Dry silica
soils tend to be higher resistance than wet or moist clay soils, thus
normally requiring either a fairly deep penetration or more than one earth
stake to achieve a low enough resistance earth.

There's bound to be a good sparkie who reads this NG who knows the
regulations and what methods are legal.

Cheers,
Alan
 
"Alan Rutlidge" <don't_spam_me_rutlidge@iinet.net.au> wrote in message
news:44727391$0$3661$5a62ac22@per-qv1-newsreader-01.iinet.net.au...
"Mathew Tiede" <MatTiede@bigpond.com> wrote in message
news:sfqcg.8925$S7.7003@news-server.bigpond.net.au...

"Phil Allison" <philallison@tpg.com.au> wrote in message
news:4dbel6F19d9t5U1@individual.net...

"Dave"

There have been several cases I know of where caravans fitted with
inverters
have been hard wired to the 240 V reticulated wiring. Two of these
cases
were on private properties where the owner did the installation
themselves.
The inverters worked OK on the DC source but of course as soon as the
vans
were hooked up to the house power - well one burned to the ground and
the
other resulted in a non-fatal electric shock (no RCDs in the house
wiring
and connected via extension cords through the kitchen and bedroom
windows).

In another case the inverter was installed by an electrician (wired in
permanently) who then complained to the supplier when it blew itself to
pieces when the mains was connected (again to a non-RCD protected
domestic
GPO). His letter to the supplier makes interesting reading as it
demonstrates the profound lack of knowledge on his part, and the lack
of
foresight on behalf of the supplier/manufacturer in not warning about
not
installing the device that way.

2> possible earthing issues. Since a caravan is electrically
insulated from terra firma, unlike a house which has its own earth
stake, I dont know what the proper procedure should be for caravan
earthing, when run off a generator or inverter - that likely isnt
earthed either.

Usually there are 'earth' connections to the frame or metal enclosure
of the
gen/inv itself. These don't function like the earth in a mains
installation
as there is no MEN connection on the gen/inv output, the earth is for
static
dissipation rather than safety.. The output of the generator or
inverter is
floating, the earth pin on the output is connected to frame ground and
is
safe enough (to a degree) with respect to faults to exposed metal of
devices
connected to the output. It would require a double fault for a serious
hazard to arise (one fault in the gen/inv insulation system and one in
the
appliance).

In addition to inverters there are a few cases involving camping
generators
being similarly wired in permanently within motor homes and carvans.
The
alternators in the smaller camping generaotrs burn very nicely on a 15A
GPO
until either they melt open circuit or they short to frame, in which
case
the RCD in the supply should cut in. We did this to one last month to
show
an importer why they really should have a warning in the instructions.

My company has been investigating and advising importers about these
issues
for at least two years. The problem being few of the importers have
any
knowledge of mains power systems. They just see the product at a trade
show
in China and sell it, with the consequences being dealt with as they
arise
since they were never foreseen and planned for (proper instructions,
warnings, etc).



** Would seem the message got through to Altronics at least.

That is a good sign.

Since it took 20 years for the same pimply faced * fuckwits* to figure
out what the codes "A" and "B" indicated on the pots they were selling
everyone.





....... Phil


I read with intrest comments made to this post.
I do also use an inverter and a genny(not at the same time) to mains
power my caravan.
There is no possibillity for a second mains supply as I connect either to
the
20 amp socket input on the outside of the van.
The groups mention of the earth issue got me thinking......
What would be the best way tho earth the caravan frame?
If I use an earth stake how long and how deep should that be?
Mathew

Earthing the metal body of the caravan is a good precautionary way of
reducing the possibility of electric shock due to an electrical fault.
The length and depth you bury the earth stake depends on a number of
factors, but mainly the conductivity of the surrounding soil. Dry silica
soils tend to be higher resistance than wet or moist clay soils, thus
normally requiring either a fairly deep penetration or more than one earth
stake to achieve a low enough resistance earth.

There's bound to be a good sparkie who reads this NG who knows the
regulations and what methods are legal.

Cheers,
Alan
Click to expand...
Forgot to add that the earth wire should most likely be 6mm2 copper with
green/yellow insulation.
 
"Mathew Tiede" <MatTiede@bigpond.com> wrote in message
news:sfqcg.8925$S7.7003@news-server.bigpond.net.au...
"Phil Allison" <philallison@tpg.com.au> wrote in message
news:4dbel6F19d9t5U1@individual.net...

"Dave"

There have been several cases I know of where caravans fitted with
inverters
have been hard wired to the 240 V reticulated wiring. Two of these
cases
were on private properties where the owner did the installation
themselves.
The inverters worked OK on the DC source but of course as soon as the
vans
were hooked up to the house power - well one burned to the ground and
the
other resulted in a non-fatal electric shock (no RCDs in the house
wiring
and connected via extension cords through the kitchen and bedroom
windows).

In another case the inverter was installed by an electrician (wired in
permanently) who then complained to the supplier when it blew itself to
pieces when the mains was connected (again to a non-RCD protected
domestic
GPO). His letter to the supplier makes interesting reading as it
demonstrates the profound lack of knowledge on his part, and the lack
of
foresight on behalf of the supplier/manufacturer in not warning about
not
installing the device that way.

2> possible earthing issues. Since a caravan is electrically
insulated from terra firma, unlike a house which has its own earth
stake, I dont know what the proper procedure should be for caravan
earthing, when run off a generator or inverter - that likely isnt
earthed either.

Usually there are 'earth' connections to the frame or metal enclosure
of
the
gen/inv itself. These don't function like the earth in a mains
installation
as there is no MEN connection on the gen/inv output, the earth is for
static
dissipation rather than safety.. The output of the generator or
inverter
is
floating, the earth pin on the output is connected to frame ground and
is
safe enough (to a degree) with respect to faults to exposed metal of
devices
connected to the output. It would require a double fault for a serious
hazard to arise (one fault in the gen/inv insulation system and one in
the
appliance).

In addition to inverters there are a few cases involving camping
generators
being similarly wired in permanently within motor homes and carvans.
The
alternators in the smaller camping generaotrs burn very nicely on a 15A
GPO
until either they melt open circuit or they short to frame, in which
case
the RCD in the supply should cut in. We did this to one last month to
show
an importer why they really should have a warning in the instructions.

My company has been investigating and advising importers about these
issues
for at least two years. The problem being few of the importers have
any
knowledge of mains power systems. They just see the product at a trade
show
in China and sell it, with the consequences being dealt with as they
arise
since they were never foreseen and planned for (proper instructions,
warnings, etc).



** Would seem the message got through to Altronics at least.

That is a good sign.

Since it took 20 years for the same pimply faced * fuckwits* to figure
out what the codes "A" and "B" indicated on the pots they were selling
everyone.





....... Phil


I read with intrest comments made to this post.
I do also use an inverter and a genny(not at the same time) to mains power
my caravan.
There is no possibillity for a second mains supply as I connect either to
the
20 amp socket input on the outside of the van.
The groups mention of the earth issue got me thinking......
What would be the best way tho earth the caravan frame?
If I use an earth stake how long and how deep should that be?
Mathew
Click to expand...
I am the same Dave/David that replied above... different office... different
PC...

The earth pin the 20 A inlet would be bonded to the frame of the van, and
would also be bonded to the generator frame. Earthing a genny or inverter
does not provide the type of protection that earthing does for a mains
supply - there is no MEN connection in an invertor or generator and so a
fault between active and earth would not trip a circuit breaker (note - some
gensets are fitted with RCDs and these have an MEN connection**). Earthing
the van won't harm anything if you are running from a genset/inverter, but
it doesn't make it safer either.

** One importer has been removing the power outlet from chinese made
gensets and replacing them with Clipsal RCD integrated power points to make
the genset "safer". They couldn't work out why customers were returning
them under warranty because the RCD wouldn't function (failed when tested
with RCD capable PATS). Clipsal claim the RCDs are functioning perfectly.
Why don't they work?
.......
Because the importer knows SFA about electrical/electronics and didn't make
an MEN connection on the alternator side of the RCD (they just did a wire
for wire changeover). So the expensive RCD GPO functions just the same as
the plain old GPO it replaced.
 
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