Electric motors

[Robert Atkinson 2Participant @robertatkinson2]

I was not implying that all chinese items are junk, but this is

The metal bodied connectors used for the motor power and feedback are not safe for use on the voltages that the motor runs on.

Trouble is people ignore the rules due to "normalisation" of the supply and use of non-compliant items – until someone dies then the fertiliser hits the air mover. Then there is a clamp down or / and knee-jerk legislation that also affects the people who were doing the right thing as well as the chancers.
An example of this is the proposal to make e-bike compliance subject to 3rd party review. This will add cost and delay to market for responsibe manufacturers whose bike wrer already safe. The chancers will just print false documents. I've seen this with pulse oximeters. Bought one that was CE marked an had a notiifed body reference. On checking it turns out thet notified bod don't do pulse oximeters

Robert.

[not done it yetParticipant @notdoneityet]

Posted by Robert Atkinson 2 on 24/08/2023 07:56:59:

I was not implying that all chinese items are junk, but this is

The metal bodied connectors used for the motor power and feedback are not safe for use on the voltages that the motor runs on.

Trouble is people ignore the rules due to "normalisation" of the supply and use of non-compliant items – until someone dies then the fertiliser hits the air mover. Then there is a clamp down or / and knee-jerk legislation that also affects the people who were doing the right thing as well as the chancers.
An example of this is the proposal to make e-bike compliance subject to 3rd party review. This will add cost and delay to market for responsibe manufacturers whose bike wrer already safe. The chancers will just print false documents. I've seen this with pulse oximeters. Bought one that was CE marked an had a notiifed body reference. On checking it turns out thet notified bod don't do pulse oximeters

Robert.

Exactly spot on, correct and already slowly being realised by the authorities.

One clear example was the Trading Standards seizing of approximately a thousand cheap chinese diesel air heaters. late last year. These heaters, while being cheap and likely without the best of instructions, were (IMO0) ‘satisfactory’ for the purpose for which they were designed – if used responsibly. They were offered as vehicle parking heaters, not for installing inside habitable buildings, which has become a popular use – according to the number of youtube videos on their use.

But lets agree, here, that lots of things are used for purposes they were not designed for. One example is the alarming number of knife-crime threats, injuries and deaths – using tools, designed for kitchen (or other legal applications) as weapons.

[CirclipParticipant @circlip]

Thought "CE" meant Chinese Export on oriental offerings?

Regards Ian

[mgnbukParticipant @mgnbuk]

Is it the particular metal body connectors used on that Chinese drive that you are not happy about Robert ?

All the Indramat, Siemens & Fanuc servomotors that use cable mounted connectors (rather than connecting boxes) I installed used metal body connectors.

Nigel B

[Robert Atkinson 2Participant @robertatkinson2]

Posted by mgnbuk on 24/08/2023 15:34:06:

Is it the particular metal body connectors used on that Chinese drive that you are not happy about Robert ?

All the Indramat, Siemens & Fanuc servomotors that use cable mounted connectors (rather than connecting boxes) I installed used metal body connectors.

Nigel B

Yes.
The connectors on the servodrives you used are designed for the purpose like these:
https://lapplimited.lappgroup.com/products/online-catalogue/products/epic-industrial-connectors/circular-connectors/epic-power-ls1/epic-power-ls1-d6.html
Note the range here:
https://lapplimited.lappgroup.com/products/online-catalogue/epic-industrial-connectors.html
includes power and signal variants.

The connector on the chinese unit are a type designed for low voltage DC. They date back to at least the 60's. A common applictaion was micropones on CB radios and the like.

Robert.

[Robert Atkinson 2Participant @robertatkinson2]

The connectors on the chinese motor control are sometiems called "aviation" connectors. This vendor
http://www.ebay.co.uk/itm/283143222904?
says they are rated for 400V and 10A. They may not break down at that but there is no engineered means of earthing the metal body of the free connector. They do not have a "make first break last" protective earth contact. They don't have the creapage and clearance distances required to meet international safety standards for >50V use.

To make thing worse. They have used a MALE connector on the OUTPUT to the motor. This means there are exposed pins with high voltage on them when the motor is unplugged. This is a serious shock risk.

Robert.

[Author]

Posts