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!


2017 NEC and Related
2017 NEC
Now Available!

Recent Posts
Parking lot pole light swap....
by gfretwell
Yesterday at 11:04 PM
International Wire Colour Codes
by Tjia1981
Yesterday at 12:08 PM
Son of Sparky
by HotLine1
10/20/16 07:43 PM
Speaking of Plugmold ...
by gfretwell
10/17/16 02:37 PM
Broken battery charger? Check for cobwebs!
by gfretwell
10/17/16 02:30 PM
New in the Gallery:
12.5A through 0.75mm˛ flex (just out of curiosity)
Shout Box

Top Posters (30 Days)
gfretwell 13
HotLine1 7
ghost307 6
renosteinke 6
Potseal 4
Who's Online
0 registered (), 221 Guests and 6 Spiders online.
Key: Admin, Global Mod, Mod
Topic Options
Rate This Topic
#162024 - 04/11/07 09:03 PM Fire Alarm Conductors
RobbieD Offline

Registered: 02/23/03
Posts: 238
Loc: Canada
I know that if you are using stranded conductors with more then 7 strands you must bunch tin them or use a proper compression clamp. My question is WRT the wires in the Fire Alarm devices.

Say for example a listed device such as a supervised sprinkler valve. Inside the listed device is a micro switch with stranded copper conductors. Must these also be tinned even though it is a listed device or does that just apply to the condustors that we are bringing to the device?

I know that it would make sense to tin them but if it is required then why don't the manufacturers do it?

Just wondering if i have to get the soldering iron out to tin the conductors that are part of the listed assembly. Any help appreciated.


2014 / 2011 NEC & Related Books and Study Guides
#162034 - 04/12/07 07:13 AM Re: Fire Alarm Conductors [Re: RobbieD]
jay8 Offline

Registered: 07/28/05
Posts: 183
Loc: Vancouver, BC
What I usually use is the crimp on wire caps if I am bringing stranded wire to the device, this covers the rule, I believe, since all wires are covered under an appropriate crimped connector. I also find stranded wires from the factory come tinned, unless you cut the wire and loose the tinned end.

#162139 - 04/13/07 02:45 PM Re: Fire Alarm Conductors [Re: jay8]
RobbieD Offline

Registered: 02/23/03
Posts: 238
Loc: Canada
Still asking the question.
These wires were not cut, that is the way they came with the valve.

#162234 - 04/14/07 11:18 PM Re: Fire Alarm Conductors [Re: RobbieD]
Check Pilot Offline

Registered: 11/25/05
Posts: 145
Loc: Edmonton Alberta Canada
I always tin any stranded conductors and usually even go so far as to solder the stranded to the solid before putting on a wire nut. It does take a few more minutes to do, but I know the connection will not likely provide an opportunity for future corrosion and problems with intermittent troubles down the road.

#162263 - 04/15/07 08:17 PM Re: Fire Alarm Conductors [Re: Check Pilot]
LarryC Offline

Registered: 07/05/04
Posts: 776
Loc: Winchester, NH, US
 Originally Posted By: Check Pilot
I always tin any stranded conductors

One thing to watch out for when tinning stranded conductors, using them under a compression style connector can result in the failure of the connection. The soldered bundle of wire strands may fracture and break apart under compression, resulting in a loose connection.

I use the soft copper ferrules when terminating small stranded wires (16-24 AWG) in control panels for industrial applications.

#162410 - 04/18/07 08:03 PM Re: Fire Alarm Conductors [Re: Check Pilot]
twh Offline

Registered: 03/11/04
Posts: 895
Loc: Regina, Sask.
If you solder the wires together, in the device, how do you separate the wires during the verification process?


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