Biomass Electrical Earthing

[Hobbs]

Hi all, I have a question and despite my 15+ years as an electrician its a relatively basic one.:blush5:

When earthing what is the situation with the following:

I have a Biomass Boiler installed with the pellet feed pipes made of plastic pipes (possibly a bit weak for the pellets to be blown in but its the plumbers/fitters idea so go figure) and a metal connection point fitted to the plastic pipe and mounted in a brick wall.
I have been told it needs earthing but i cant for the life of me figure out why.

its an extreanous metal part agreed but its isolated from all parts by the plastic pipe and the wall its mounted into.
if im to connect an earth to this as asked why do we not for example bond all radiators that are inside the house and fitted to poly pipe? those are also extreaneous i would have thought?

im guessing im being thick but any help you guys can give me would be much appreciated.

 

[jackhammerJIM]

are you referring to the vacuum feed pipes ?

if so its because the tubes can create static . the ones we fit have ann inner core of copper inside the plastic tubing . manufacturers instructions state the copper core should be connected to the earth of the boiler .

what are you saying is an extraneous part ?

 

[polo1]

Hi all, I have a question and despite my 15+ years as an electrician its a relatively basic one.:blush5:

When earthing what is the situation with the following:

I have a Biomass Boiler installed with the pellet feed pipes made of plastic pipes (possibly a bit weak for the pellets to be blown in but its the plumbers/fitters idea so go figure) and a metal connection point fitted to the plastic pipe and mounted in a brick wall.
I have been told it needs earthing but i cant for the life of me figure out why.

its an extreanous metal part agreed but its isolated from all parts by the plastic pipe and the wall its mounted into.
if im to connect an earth to this as asked why do we not for example bond all radiators that are inside the house and fitted to poly pipe? those are also extreaneous i would have thought?

im guessing im being thick but any help you guys can give me would be much appreciated.

Simples, follow manufacturer's instructions and/or test it to see if it is introducing an earth potential :angel_smile:

 

[Hobbs]

Simples, follow manufacturer's instructions and/or test it to see if it is introducing an earth potential :angel_smile:

unfortunatly the install manuals dont say... its the commisioning guy from the company that makes them that is saying it needs it. unfortunately the track record for these "experts" is not good... they seem pretty useless... the biomass guy 1 and 2 both left the company so there is none that know a great deal mor than us.

 

[Hobbs]

are you referring to the vacuum feed pipes ?

if so its because the tubes can create static . the ones we fit have ann inner core of copper inside the plastic tubing . manufacturers instructions state the copper core should be connected to the earth of the boiler .

what are you saying is an extraneous part ?

yes ive seen the tubes with copper this isnt the case on this one as its been "made" by the fitters.

the bit im on about is the metal part the lorry puts its hose on to to fill the storage room.

 

[snowhead]

yes ive seen the tubes with copper this isnt the case on this one as its been "made" by the fitters.

the bit im on about is the metal part the lorry puts its hose on to to fill the storage room.

It's for Static earthing of the delivery tanker, nothing to do with the Building Electrical installation.
Sparks and Wood dust don't make a good combination.

 

[jackhammerJIM]

The filler pipes do not require bonding they are not extraneous

 

[stevey1983]

As snowhead has said it is for static and needs bonding otherwise the driver may get a shock when disconnecting the pipes after filling and also possible for an explosion

 

[thebigcheese]

Would you not want the pipe to be completely isolated from earth then so the 'static' cannot find a path to travel down?

 

[Bobster]

Would you not want the pipe to be completely isolated from earth then so the 'static' cannot find a path to travel down?

Think about why that would be a bad idea in a potentially Ex environment.

 

[Knobhead]

yes ive seen the tubes with copper this isnt the case on this one as its been "made" by the fitters.

the bit im on about is the metal part the lorry puts its hose on to to fill the storage room.

Fitters who clearly don’t know what they are doing. By the sounds of it you need to have a major rethink on this before you have an explosion and fire on your hands.

 

[Barry White]

Wood dust mixed with the correct proportion of air is a highly explosive mixture! ( the wood dust is blown in so highly likley to reach this mixture sometimes) the filler pipe must be earthed to stop a discharge igniting this. Also there must be no electrical sockets lights or other electrical equipment in the store unless specially constructed for this atmosphere and approved for use therin.

heres a link to a supplier of pellets delivery checklist

https://www.woodpellets2u.co.uk/bulk-blown-wood-pellet-delivery-check-list

 

[Knobhead]

A good link, it spells it out as it should be. I just hope the OP looks at it. For one thing he’s in the same county as me, I’ve not very healthy but I’d rather not be sat on a cloud playing a harp just yet.

I had a series of nasty explosions on a pulverised coal plant. The fitters had changed a section of pipework and not put the earth jumper straps back. The plant was designed to contain an explosion and vent though blast relief doors.

Even knowing that you still need to go and change your underpants when it happens. It’s quite regular during start up or shutdown as the coal concentration in the airflow will go through the range of upper and lower limits. Once running the concentration is well above the upper fire limit so fairly safe.

 

[snowhead]

Would you not want the pipe to be completely isolated from earth then so the 'static' cannot find a path to travel down?

You need to guarantee the delivery vehicle is static free to prevent discharge as the delivery pipe is attached to the hopper, silo or whatever.
Vehicles can build up high static charges.

There are many bulk materials that are a risk some not as obvious as petrol etc.

A few;
https://www.osha.gov/Publications/combustibledustposter.pdf

 

[Knobhead]

I hope the OP is taking this onboard. If something goes wrong I wouldn’t like to be in his shoes, if he not injured he will be for the high jump legally.