Joe, I will get a shielded cable for the motor leads, and will ground the cable, and will also add those filters. If I recall correctly, the cables from the motors connected to the main terminal block, are not that shielded, so if I shield the cables going from drives to terminal block, it is only half the battle.
i
ez.co.uk/lucas.html
=A0 =A0 =A0 =A0 =A0-- Samuel Butler- Hide quoted text -
Good one. I used to earn my living working on british bikes, trying to keep the smoke in.
You can get flexible metal conduit (Greenfield) at Depot or Lowe's and fish your motor (both spindle and servos) through the conduit to provide shielding. It's cheap stuff, I just got a 25' roll of 1/2" FMC at Depot for $10. They also have 3/8" size which may be better for the servo power leads.
I bought some from Amazon - they have a vendor that sells it - but via Amazon. I get free shipping from the Big A - otherwise there are other vendors. IIRC, it is a Intel design/developed - maybe just approved.
I'm gluing a heat sink on my SATA drive chip. It burned up on the last motherboard in the shop.
And thanks for the input.
Mart>
Either will work. As will regular conduit in areas not requiring flexibility. Nor is there any harm in doing both shielded wire and conduit, although there is no electrical advantage either. Greenfield and conduit are immune to hot chips melting a hole, though.
It's important to ground the shield where it passes through a shield wall, like the motor case and the cabinet where the VFD lives. If the VFD isn't in a metal cabinet, then ground the VFD end to the frame of the VFD.
For the record, this VFD ground is an extension of the safety (green/bare) ground system, and not the neutral (white).
I'm suspicious of the VFD terminal block - it may be the power neutral, versus the safety ground. The VFD frame ground (usually with green screw) is safe and correct.
They also make line inductors that go between VFD and motor that reduce interference by reducing the edge speed of the switched waveform that the motor sees as a varying-frequency sine wave. However, such inductors are very big and expensive, and very unlikely to be needed for such a small motor. (I have no such thing on my VFDs.)
Joe Gwinn
Jon, I bought some of those rings at digikey, they were inexpensive. Item 240-2131-ND.
So you say, basically, just put a pair wires through the hole of one ring, right?
i
Joe, I bought those rings. I will shield the wires going to the big terminal block from the drives, (and ground the shield) and would put the rings on the wires going out of the terminal block to the motors.
i
Cheap enough to just try. One normally puts all three (or four) motor leads through the same core, so the power-frequency magnetic fields largely cancel, to avoid magnetic saturation of the ferrite. One can put multiple cores on the same cable, one after another. Nor will anything bad or permanent happen if you do put a single wire through a core, perhaps saturating the ferrite, so there is no reason not to try everything.
Joe Gwinn
I will put them on tonight.
iWhat diameter of wire hole ? - need any ribbon ones - have them. I think I have several like you mention from industrial equipment use.
I have a 3 phase, 50 amp RF line filter that I ran out of room to use. Have AT NIC and modern NIC , various SIMS. e.g. HP printers and old pc's.
Let me know. Should be easy to get my hands on them.
Mart> >> >>
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