Enclosure damage

AJITNAYAK

Attachment not found.Dear all,

I am trying to find reason for crack in this below enclosure. We have proper ventilation glands in enclosure boxes and holes made as per description for vendor . Is there any valid reason for such damage

In 150 boxes we found 140 no got damaged


Here Base - Polyester & Lid - Polycarbonate. I am wounder reason for breakage in huge amount.

relevant switch attached below
http://www.newark.com/abb-control/ohb45j6/handle-pistol-blk-switch/dp/91R1374

Blackcherry04

Re: Enclosure damage

Hard to tell what the cover is made of, Lexan, Plexiglass ? My guess is the plastic was stressed by heat when the hole was drilled. Many times the cracks will not appear for Weeks / Months after the hole is drilled. Holes are best drilled with a counterbore bit with a lubricant in some plastics.

James

Re: Enclosure damage

looks to be acrylic plastic.
Holes should be drilled with a negative rake drilling edge bit.
All holes drilles should be followed with a slight countersink bit on both side of hole to relieve surface tension.

AJITNAYAK

Re: Enclosure damage

Let me know how to resolve the issue.If we make in such enclosure what are standard procees to be followed. What we need to check on material side before making hole

BB.

Re: Enclosure damage

Also, edges of hole should be relatively smooth (deburred, good drilling technique to reduce chipping).

Possibly look to using a "tougher" plastic (like Lexan). Others can be brittle and relatively easy to crack when subjected to stress (like a switch mounting).

Plastics exposed to sun/ultra violet lights can become brittle.

And do you need a fire rated material for your enclosure? Possibly anti-static (to reduce dust attraction).

-Bill