Isolating a motor

Post Reply
Aussie 3 railer
Posts: 61
Joined: Mon Jul 15, 2024 2:24 am
Contact:

Isolating a motor

#1

Post by Aussie 3 railer »

Hello all again.

Busy day here today lots of questions. I keep reading where the motor needs to be isolated or insulated. Bit confused here and probably miss understanding the term. Can someone enlighten me please.

Dirk
User avatar
Rog (RJ)
Posts: 572
Joined: Thu Oct 04, 2018 5:49 pm
Location: South Nottingham
Contact:

Re: Isolating a motor

#2

Post by Rog (RJ) »

All it means is that the motor's electrical connections must be isolated so that there can be no contact with the chassis (if it's live) or the connections to the pickups or rails. Any electrical connection will destroy the decoder.

Ringfield motors often have the left hand brush connected to the chassis and this connection must be removed.
Mountain Goat
Posts: 1554
Joined: Fri Oct 05, 2018 12:57 pm
Contact:

Re: Isolating a motor

#3

Post by Mountain Goat »

The need to isolate motor connections is if one needs to hard wire a DCC decoder in the locomotive. If one runs on ordinary 12v DC, one does not need to worry about it. Is only the DCC'ers need worry about motor isolation.
Budget modelling in 0-16.5...
Aussie 3 railer
Posts: 61
Joined: Mon Jul 15, 2024 2:24 am
Contact:

Re: Isolating a motor

#4

Post by Aussie 3 railer »

Bit confusing here. The motor is mounted, screwed to the chassis. The output shaft is in contact with the worm and wheel which is in contact with the chassis. I understand the motor wiring (2 wires) is connected directly to the decoder.

Dirk
User avatar
Brian
Posts: 2232
Joined: Thu Oct 04, 2018 3:49 pm
Location: SE Kent
Contact:

Re: Isolating a motor

#5

Post by Brian »

If there is any connection between the decoders output wires (Orange and Grey) that go directly to the motor, upon placing the loco onto DCC powered rails it will immediately cause the decoder to fail. Usually terminally! Hence the need to test both motor connections once the old DC wiring has been removed from the motor, testing each motor tab to the wheels and where necessary any metal mount / chassis. Any test showing a connection MUST be corrected to remove the connection before proceeding with the rest of the decoder installation.

There must never be any track power connection to the decoders output.

Equally you should never apply an external DC voltage directly to the motor with the decoder still connected to the motor. If a DC power is applied with the decoder still connected to the motor the decoder will terminally fail usually in a puff of smoke! :o
Image << Click the Icon to go to my website
User avatar
RAF96
Posts: 534
Joined: Fri Oct 05, 2018 6:33 am
Location: Dereham, Norfolk, UK
Contact:

Re: Isolating a motor

#6

Post by RAF96 »

Given your username, by chance are you trying to convert 3-rail locos to DCC.
Aussie 3 railer
Posts: 61
Joined: Mon Jul 15, 2024 2:24 am
Contact:

Re: Isolating a motor

#7

Post by Aussie 3 railer »

Hello RAF, no I've given the 3 rail system away after I caught this DCC diaease. Since then is been a very sharp learning experience and I am indetted to so many people here for the guidance. I am living it daily now and loving it.

Dirk
Aussie 3 railer
Posts: 61
Joined: Mon Jul 15, 2024 2:24 am
Contact:

Re: Isolating a motor

#8

Post by Aussie 3 railer »

Many thanks Brian and to everyone else who helped. I am with it nowat last..

Dirk
Post Reply

Who is online

Users browsing this forum: No registered users and 2 guests