Quick Splice Recommendation

Suit case connectors. 

No need to solder.

Dave

david1 posted:

Suit case connectors. 

No need to solder.

Dave

It's a 3M 905 - slide the open side over the run - insert the tap wire into the innermost hole, and squeeze with slip jaw pliers opened up for a more square compression. The special tool is expensive.

Here is one vendor, but you can search others -

I used to be a Product Manager for a company that sold electrical connection devices for industrial maintenance, including small-gauge (22 and smaller) up to huge (magnet crane) connectors.

A few things that some might find interesting:

- electricity in small voltages (240 and less) is carried over the SURFACE of the conductor/ wires, not through the center/core.  This is why keeping the surfaces of our rails clean and oxidation-free is so important.  A rail made of tubing is therefore just as good as would be a solid rail.  Nickel Silver rail resists oxidation better than steel, brass or plated rail, because the surface stays cleaner.

- the larger the wire, hence the more surface area, the more current (amperage or milliamps) the wire will carry.

- voltage is important for "pushing" electrons over a conductor for a greater distance; amperage is important for running devices.  At our low voltages- CLEAN is everything.  One reason the newer engines that run on 18 v seem so much more trouble-free than did the older engines is that there is a higher constant voltage to the track and the current (amperage) is transmitted better through the layout. 

- If you used too small of a conductor (say a 22 gauge buss wire for the layout vs. a 16-14 AWG (American Wire Gauge) wire), then the current does not get transmitted as efficiently- smaller surface area.

Regarding connectors:  any quality CRIMP connector is more efficient than even a soldered joint, because the connector cuts into the outer surface of the wire.  A soldered connection can have many faults- cold solder joints, poor solder conductivity etc.

So- assuming you get a reliable cut through the insulation of the wire, the connection of a suitcase connector should be solid. 

Maintenance people say negative things about crimp butt connectors, or suitcase connectors, because in their experience, using them a lot can result in failures, mainly because of poor installation/ in a hurry or vibration in a machine environment.

- electricity in small voltages (240 and less) is carried over the SURFACE of the conductor/ wires, not through the center/core.  This is why keeping the surfaces of our rails clean and oxidation-free is so important.  A rail made of tubing is therefore just as good as would be a solid rail.  Nickel Silver rail resists oxidation better than steel, brass or plated rail, because the surface stays cleaner.

Are you referring to the "skin effect"?

If so, the skin effect is proportional to the frequency of the A.C., and is negligible at 60 hertz. There is a formula to calculate the effect at whatever frequency the various train control systems use.

Mike Wyatt posted:

 

Snip....

Maintenance people say negative things about crimp butt connectors, or suitcase connectors, because in their experience, using them a lot can result in failures, mainly because of poor installation/ in a hurry or vibration in a machine environment.

Exactly why I don't like them! Most of them that I have been around were not crimped properly nore was the proper crimping tool used to crimp them. Probably not the fault of the people using them, but lack of proper training on their use? If people were better educated on proper installation/tools, things would be much better. Their reputation would possibly improve as well. Loose crimp connectors are a real trouble shooting nightmare! I grew to hate them during my working life! However, there are folks here on this forum that I would trust a crimp connection from!

rtr12 posted:

Mike Wyatt posted:

 

Snip....

Maintenance people say negative things about crimp butt connectors, or suitcase connectors, because in their experience, using them a lot can result in failures, mainly because of poor installation/ in a hurry or vibration in a machine environment.

Exactly why I don't like them! Most of them that I have been around were not crimped properly nore was the proper crimping tool used to crimp them. Probably not the fault of the people using them, but lack of proper training on their use? If people were better educated on proper installation/tools, things would be much better. Their reputation would possibly improve as well. Loose crimp connectors are a real trouble shooting nightmare! I grew to hate them during my working life! However, there are folks here on this forum that I would trust a crimp connection from!

The 3M tap splices do not crimp - a dual slotted metal piece slides down and cuts through the insulating sheath and contacts the wire and locks down . The flap is just a cover.

Crimping does take care and experience with the proper tool.

I was referring only to the 'crimp butt connectors' Mike also mentioned in his post and people saying negative things about them. Guess I should have been more specific...

I know what the 3M 'suitcase' connectors are, but have had very little experience with them. They were seldom used in my line of work, before I retired anyway. Don't they recommend a special 'crimper' for those as well? I know they are trying to sell things...but don't know how necessary the special tool is for a proper connection? I do know that using the wrong one  for your wire size can cause problems, but that's about all.

I've had excellent luck with These.

Bruce

Mike Wyatt posted:

- electricity in small voltages (240 and less) is carried over the SURFACE of the conductor/ wires, not through the center/core.  This is why keeping the surfaces of our rails clean and oxidation-free is so important.  A rail made of tubing is therefore just as good as would be a solid rail.  Nickel Silver rail resists oxidation better than steel, brass or plated rail, because the surface stays cleaner.

- the larger the wire, hence the more surface area, the more current (amperage or milliamps) the wire will carry.

A couple of corrections.  What you are referring to is called skin-effect.  The behavior is the same for any voltage, AAMOF, the folks that design high voltage transmission systems take that into account, but they have really large diameter conductors.

Skin-effect of 60hz power goes deep, and nothing you're going to wire your layout with will see that effect.  At 60hz, skin effect of copper wire is 8417um, that's about .33".  So, unless your wire is over .66" in diameter, all of the conductor will be used for power.  There will be slightly more of the current flowing on the surface, but for any wire we'll be using, the current difference throughout the conductor will be insignificant.