The Electrical Contractor Network

ECN Electrical Forum
Discussion Forums for Electricians, Inspectors and Related Professionals

Books, Tools and Test Equipment for Electrical and Construction Trades

Register Now!

Register Now!

We want your input!

Featured:
   

2017 NEC and Related
2017 NEC
Now Available!

   
Recent Posts
International Wire Colour Codes
by Texas_Ranger
Today at 03:29 PM
Looking for older post
by Texas_Ranger
Today at 03:22 PM
Safety at heights?
by gfretwell
Today at 02:19 AM
Last time to chat here
by Trumpy
Yesterday at 11:41 PM
Unsafe Situations
by Trumpy
Yesterday at 09:46 PM
New in the Gallery:
Desk-mounted "power-board"
Shout Box

Top Posters (30 Days)
Admin 35
HotLine1 20
Trumpy 19
Ruben Rocha 17
gfretwell 16
Who's Online
1 registered (Admin), 163 Guests and 10 Spiders online.
Key: Admin, Global Mod, Mod
Topic Options
Rate This Topic
#147591 - 12/19/02 12:04 PM Double Insulated Tools
eagle1 Offline
Junior Member

Registered: 12/19/02
Posts: 1
Loc: Lancaster, SC
Having trouble finding meaningful info on the certification "Double Insulated" on electrical tools. Can metal case drill motors (for instance) be certified double insulated?

Top
Arc Flash PPE Clothing, LOTO & Insulated Tools
#147592 - 12/19/02 12:25 PM Re: Double Insulated Tools
C-H Offline


Member

Registered: 09/17/02
Posts: 1508
Loc: Stockholm, Sweden
"Double insulated" means that the tool has double or reinforced insulation. If the manufacturer has managed to get two layers of insulation between the live parts and the metal case, the tool is indeed double insulated. Electrical drills have plastic gears, thereby insulating the motor from the metal case.

Internationally, there are four classes of insulation:

Class 0: Single insulation, exposed metal parts not grounded
Class 1: Single insulation, exposed metal parts grounded
Class 2: Double or reinforced insulation
Class 3: Extra low voltage, no additional protection needed.

I Googled the net for some wise words on this and found the following lines:

--------------
Class I equipment will provide the user with two levels of protection. The innermost level is the functional or basic insulation covering live internal parts. The second level of protection is provided by a conductive case, which is earthed.

Class 2 equipment also provides the user with two levels of protection, both levels being provided by insulation. The first protective barrier is the functional or basic insulation while the outer protective layer is known as the supplementary insulation and may comprise either of an insulating internal lining to a conductive case or in the majority of instances, form the case itself.

[This message has been edited by C-H (edited 12-19-2002).]

Top


ECN Electrical Forums - sponsored by Electrical Contractor Network - Electrical and Code Related Discussion for Electrical Contractors, Electricians, Inspectors, Instructors, Engineers and other related Professionals