No barrier between terminals of terminal block - Page 1
Forum section: electronics / beginners

author: hifimusic
author_rank: Newbie
timestamp: November 16, 2020, 02:28:06 am
content: I purchased a PWM to control the speed of a motor but its terminal block is very cramped with no plastic barriers between the terminals. This creates a risk of a short. Are there any products (or creative ways) to make this terminal block safer?A picture of the terminal block is attached.Thanks!

author: T3sl4co1l
author_rank: Super Contributor
timestamp: November 16, 2020, 02:35:34 am
content: Yes!Desolder it and put on a real one.Or if that doesn't fit, dump the cheap Chinese crap and get a... "real" speed controller? There are probably other good reasons to do so...Tim

author: wraper
author_rank: Unknown
timestamp: November 16, 2020, 02:45:24 am
content: Just use different lugs. Your lugs are some weird shit.

author: james_s
author_rank: Super Contributor
timestamp: November 16, 2020, 06:44:06 am
content: Yeah those crimp terminals you're using are way too big for the terminal spacing on the device. You should use ring terminals that are small enough that they cannot touch if they twist around. The equipment is poorly designed but it should still work with appropriate connectors.

author: radiolistener
author_rank: Super Contributor
timestamp: November 16, 2020, 07:49:26 am
content: Quote from: hifimusic on November 16, 2020, 02:28:06 amOn the other hand it protect you from high voltage pulses, it works like high voltage surge arrester

author: Gyro
author_rank: Super Contributor
timestamp: November 16, 2020, 10:20:26 am
content: Worst case, make some insulating plastic strips and put a vertical saw cut part way though each one so that they will be retained by the sheet metal lid and between the terminals.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: November 16, 2020, 11:24:31 am
content: Quote from: radiolistener on November 16, 2020, 07:49:26 amAlthough you're very optimistic if you think that thing can handle 2kV+ surgesTim

author: Twoflower
author_rank: Frequent Contributor
timestamp: November 16, 2020, 11:28:44 am
content: Those square washers could indicate that they're designed to use the feruled cables and no terminal lugs.

author: mikerj
author_rank: Super Contributor
timestamp: November 16, 2020, 05:11:05 pm
content: Probably designed for the "fork" style terminations that don't require the screw to be removed when connecting/disconnecting a wire.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: November 19, 2020, 10:08:27 pm
content: If you bought a nasty device and can't throw it away, be consistent - remove the screws and solder the wires.

author: Vovk_Z
author_rank: Super Contributor
timestamp: November 20, 2020, 12:35:34 am
content: I would just find a smaller size lugs. The ones on a first photo are definitely too large. For this purposes I alwayse have an assortment of different ones for different sizes.It seems to me those connectors are with 3.5mm screws (imperial size ?). M4 lugs may possibly be to large so I would use M3 ones (just make a larger holes with a 3.5mm drill).

author: wraper
author_rank: Unknown
timestamp: November 20, 2020, 02:17:26 am
content: Quote from: S. Petrukhin on November 19, 2020, 10:08:27 pmFWIW these terminals are order of magnitude better than the vast majority of terminal blocks. They have 4 mounting points each, and are basically undestroyable unless you tighten the screw with so much force that rip the thread. The only issue is they are located a bit too close to each other. But it is no problem if lugs of appropriate size are used.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: November 20, 2020, 10:11:23 am
content: Quote from: wraper on November 20, 2020, 02:17:26 amI didn't say that the terminals are bad themself.