Hybrid motor starter

2011

I spent a few days recently with Phoenix Contact at one of their factories in Germany. They demonstrated a number of interesting products. One that really impressed me was their hybrid motor starter. It contains a solid state switch that prevents arcing across the contacts when making and breaking the circuit. This extends service life. In addition to having builtin overloads. All in all it reduces space too which can reduce the overall panel size.

More elaborate versions are also available which can be used to change motor direction without the requirement for additional contractors / devices.

Profinet versions also available if there is a requirement to integrate with a PLC / control system.

Pretty cool

Stoner

very good, could see them lasting a long time alright

DublinDilbert

A small amount of arc is actually sometimes good for the contacts, clears corrosion and dirt from the contacts.

Worked developing software for a series's motor controller back a number of years ago. We developed software to prevent arc'ing in the direction contacts. When it was run in the field there was some issues with the contacts corroding or getting dirty with no arc to clean them. Our solution was every 10 direction changes allow a small arc to form.

The issue was probably we were using open contactors in dirty environments. I'm sure Phoenix have figured it all out.

2011

The point that you raise never occurred to me to be honest. I generally think how can we reduce the arc to reduce wear. I have sent it to Phoenix, will be interesting to see how they respond. I will let you know.

Bruthal

2011 wrote: »

The point that you raise never occurred to me to be honest. I generally think how can we reduce the arc to reduce wear. I have sent it to Phoenix, will be interesting to see how they respond. I will let you know.

Sealed inside an enclosure helps keep dirt out anyway. Corrosion reduced by the contact metal used possibly. Nice gold contacts or similar maybe. I seen it somewhere about it before. A small arc, but not too small, now and again apparently seemed an advantage to keeping contacts clean from corrosion alright.

2011

Bruthal wrote: »

Sealed inside an enclosure helps keep dirt out anyway. Corrosion reduced by the contact metal used possibly.

Until very recently I would have thought the same. However Phoenix Contact showed us a presentation on the advantage of solid state relays over electromagnetical. They explained that only the soils state relays could guarantee no particulate contamination. This contributed to a improved MTBF values they explained.

Bruthal

2011 wrote: »

Until very recently I would have thought the same. However Phoenix Contact showed us a presentation on the advantage of solid state relays over electromagnetical. They explained that only the soils state relays could guarantee no particulate contamination. This contributed to a improved MTBF values they explained.

Well what I refer to was when mechanical contacts are used. In a dusty atmosphere, exposed contacts would be more prone to foreign particle contamination. But even sealed, there are no guarantees that they will be contamination free. They can generate their own contamination.

Solid state relays can be as simple as a transistor setup, Or optocouplers switching triacs etc. The optocoupler makes them act like a true relay with its isolation properties. When I did the tractor project that time, I was thinking about using an optocoupler and mosfet arrangement, but used car relays instead as I was running out of time for experimenting.

Steve

One thing to remember about solid state is that, while it is very reliable, when it does fail it tends to fail 'unsafe'. I'm sure a company such as Phoenix have accounted for this though, their reputation is platinum imo.
How long before we start seeing these badged as AB or Omron etc at twice the price

Fun fact about mechanical contactors: they are all designed to 'wipe' their contacts against each other after they make to self clean, this is generally where the 10x10^6 operation limit comes from.

2011

Steve wrote: »

One thing to remember about solid state is that, while it is very reliable, when it does fail it tends to fail 'unsafe'.

I would not think so in this case (assuming that safe is off / open circuit). According to the documentation under approvals/conformities:
Safety Integrity Level according to IEC 61508 SIL 3 (safe shutdown)
SIL 2 (motor protection)
Category acc. to EN ISO 13849 3 (Safe shutdown)
Performance level according to ISO 13849 e (Safe shutdown)

I'm sure a company such as Phoenix have accounted for this though, their reputation is platinum imo.

I don't work for Phoenix (nor do I intend to) so I'm not trying to push their product, I was just impressed by these devices.

How long before we start seeing these badged as AB or Omron etc at twice the price

I know that they already rebadged safety relays (I saw them being made in the factory), so I would think that you are correct

Steve

2011 wrote: »

I would not think so in this case (assuming that safe is off / open circuit). According to the documentation under approvals/conformities:
Safety Integrity Level according to IEC 61508 SIL 3 (safe shutdown)
SIL 2 (motor protection)
Category acc. to EN ISO 13849 3 (Safe shutdown)
Performance level according to ISO 13849 e (Safe shutdown)

In the case of cheap solid state switching devices, what I mean by 'fail unsafe' is that they fail to an 'on' or conducting state. You'd be surprised how many do this.

If it conforms to SIL3 / PLe then no worries there, it's solid. I wasn't saying the product you mentioned was unsafe, just that bare bones versions of it potentially are.

I don't work for Phoenix (nor do I intend to) so I'm not trying to push their product, I was just impressed by these devices.

Neither do I and I've used their stuff for many years and have had zero problems with it. in fact, if given a choice I'd recommend it.

I know that they already rebadged safety relays (I saw them being made in the factory), so I would think that you are correct

2011

Steve wrote: »

I've used their stuff for many years and have had zero problems with it.

I had used their power supply units for years and didn't know them for much else until recently. I now know that have interesting products such as a robust supercap 24VDC UPS.