Electronically commutated.I know nothing about them, but I was curious and found this site that talks about them.
We manufacture brushless DC motors and the drives for them.Are EC motors as noisy as a VFD?
Normally, for VSDs we use multi-core steel wire armoured cables for buth supply and motor. The armour is earthed (grounded) and acts as a shield. Depending in the location the cable may be run clipped to galvanised slotted cable tray fixed to walls. In a few cases, the switch rooms have a raised floor and cables are run underneath it. We haven't had noise problems.Besoeker, do you mind mentioning some of these installation methods?
Last sentence very true, but there is a huge difference in electrical noise (EMI) between ec and psm motors. I've designed (part of design team, no single person ever gets to design an aerospace piece of hardware themselves) inverter drives for commercial and military aircraft and spacecraft, and one of the biggest parts of the design job is to get the 'noise' levels down to mil-std-461, and even lower for commercial aircraft.From an electrical noise point of view, I can't see a lot of difference. Chosen installation method can make a big difference for both.
The way you are asking the questing is a bit like comparing apples and oranges. A PSC motor is not a variable speed motor by itself. So comparing it to an ECM may be a mismatch right there. But some fan suppliers in particular do offer fixed speed ECMs for the simple reason that they are about 20% more efficient than PSC motors. So in THAT context, they can be compared. However then you throw in the VFD issue, which implies you ARE asking about variable speed. In that case, you then have to ask if you mean to compare an ECM to a PSC motor using a VFD? If so, then it gets more complicated.How much more electrical noise does an EC motor create compared to a standard PSC motor? Are EC motors as noisy as a VFD?
What about any differences that might come from the ECM motor's electronics being more closely coupled to the motor instead of being located at a greater distance as might be the case with VFDs?For variable speed applications being designed from the ground up, you would compare an ECM to a VFD that can accept 1 phase input + a standard 3 phase 230V motor.
In that only viable comparison then, the difference in electrical noise is virtually nil. The noise is for the most part a result of the converter sections being Switched Mode Power Supplies, and both of them are going to be identical.
No different, it has nothing to do with the speed. Common mode noise is created as a result of the rectifier pulling current in "gulps" from the AC line and from capacitive coupling in the DC pulses on the output going to the motor windings. That is the same regardless of the motor speed, the pulses are happening at 10-15kHz.How does the electrical noise of an ECM operating at a fixed speed compare to an ECM operating at variable speed?
Common mode noise? Actually, I suppose a VFD could be worse because of motor lead length if not addressed properly, but all that can be attenuated fairly equally between the two, the technology, as Besoeker said, is virtually identical. In fact, you can by AC motors with the VFDs mounted right on them, making them almost indiscernible from an ECM, albeit the VFD is usually physically larger than the ECM power modules I've seen.What about any differences that might come from the ECM motor's electronics being more closely coupled to the motor instead of being located at a greater distance as might be the case with VFDs?
The noise generated might be comparable but the noise radiated could be quite different, yes?