IP washers

I enquired at an electrical wholesalers if they have washers for mounting glands.


Apparently no one had asked that before.

It might possibly vary with manufacturer, but IP54 / IP66 would be typical.


Example Peppers Installation Instruction


I generally buy glands with an IP seal included in the kit.

Different materials are available eg Seal options


Note, some manufacturers recommend against fibre washers where they can get wet then freeze eg CMP datasheet

I fear the box rating is only true before you make any holes in it, and after that it depends on the type of gland and if there are O rings  grooves or not-  at that point it is up to the installer to design a means of keeping the IP rating that is required.

Rubber rings, fibre washers, snotting it with mastic and  not bothering at all, followed by admitting failure and adding a drain hole seem to be the sequence of descending effectiveness.

o ring example


M.

Use of IP washers totally depends on the environment the enclosure is being installed in and also the method of entry of the gland into the enclosure.

So a few basics first, if the enclosure you are installing the gland into does not have any IP rating whatsoever then why are you wasting your time putting an IP washer on the gland? Any liquids or solid particles will just enter the enclosure via the lid or other joints.


If the enclosure does have an IP rating what is it? as no point in you fitting an IP66 gland when the enclosure is only IP54 as such best you will ever have is IP54.


IP washers MUST always sit against the enclosure body, after all thats the part that is preventing the ingress of liquids and/or solid particles.


If the entry to the enclosure is by a clearance hole, then an IP washer MUST always be fitted no matter the IP rating of the enclosure, unless the enclosure has no certified IP rating when you can jsut forget a washer alltogether if you want.


If its a threaded hole a few other things to consider, if its a hole with perpendicular threads of a medium tolerance and the depth of the threaded hole is at least 6mm deep just engaging the gland will give you IP54 without the need of using a washer. If the rating of the enclosure is greater than IP54 then you will need a IP washer if you have 6mm or less than 6mm deep threaded hole.


If the enclosure is rated greater than IP54 lets say IP66  you would need to fit a suitable IP washer plus apply suitable thread sealant if you wish to keep the rating of the enclosure.


Now washers themselves? what is the environment? Fibre washers just arent normally used outdoors they swell with moisture, freeze, get hard etc and end up breaking apart and of course not providing the purpose they should. We have nylon, teflon, rubber, silicone rubber.......... there are lots, so consider material compatibility for the environment the washers will be exposed to! Im presuming you had made that decision for the material of the enclosure and the gland itself? I have seen contractors fitting nylon washers in a chemical plant where there was solvent being used and years later the nylon washers had deformed and were basically "Running" back down the cable.


Again from my experience people have correctly fitted a stainless steel enclosure because thats whats needed for a harsh environment, but contractor then fitted a CW Brass gland!! result is gland is the weakness and eventually becomes useless.

Also remember a shroud on a gland provides no IP rating whatsoever, its only as good as the person that fits it, again in a lot of chemical and harsh environments and outdoors, shrouds arent fitted as they just collect water/chemical in them that decays the gland and can leave a nasty surprise for maintenance technicians if it fills up with acid/chemical.


So Fitting a washer or not isnt quite a simple yes/no decision.


The IP66 on the CW gland, the manufacturer is stating if you fit the gland as per their instructions on the correct cable type and within the range of the cable Max and Min outside diameter the gland will give IP66 rating, its the technician that then compromises the enclosure depending on type and depth of entry and washer material used.


If the thread is imperial or coarse or tapered you will achieve nothing with a IP washer you will need a thread sealant.


Cheers GTB

Does the gland need to make good electrical contact with the enclosure? If yes, a fibre (or nylon or rubber, etc.) washer is not likely to be suitable. If you use a banjo (on the inside) you still potentially have a problem where the bolt goes through.


So how about a Dowty washer?

There is defiantly a lot to it. So an IP55 enclosure that has a through hole with a gland fitted without a washer will only be IP 54? I have definitely seen the mastic look and holes drilled ?. 


also I take it electrical contact of the gland to the enclosure will only be an issue if the swas continuity needs to be kept isn’t. In this case isn’t the gland-gland washer-enclosure-banjo-nut sufficient?