HSD Spindles

[gerald_d]

Thanks a lot for that info Evan!

Strange, when I asked them for an electric fan (EL part of the number) version for the 3.5kW MT1073-140, they offered a slightly shorter armature MT1073-120 instead, which was way down on power. I didn't think they had the 140mm/EL combo like you have, and I see that is already 20% down on power compared to my MT1073-140 with co-ax fan. Are electric fans less efficient and compels them to reduce power, or is the fact that you have 220V while my one is 380V.....? It's a mystery....

The actual spindles are all 3-phase, your guess on the VFD converting 1ph to 3ph is correct.

Where did you connect the thermistor wires to?

[evan]

I must confess it came pre-wired from SB. And I just went and looked at it again and realized it’s a total of 7 wires INCLUDING ground.

5 wire shielded cable:
3 wires for the 3 main phases
1 wire that is spliced into two wires that come off control out put of the VFD

[gerald_d]

Evan, that sort of confirms that SB ignores the thermistor. I wouldn't want the heat gauge of my car to be disconnected.

[hespj]

Thanks for the info on the fan Phil & Evan.

Gerald, when you say ShopBot are ignoring the thermistor, are you saying one is fitted but not used? But presumably could be connected?

John

[gordon]

The thermistor in your HSD spindle is connected to the multi-function input terminals in the VFD and programmed for a N.C. connection. If the thermistor opens the drives is faulted and EF4 is displayed on the drive. One wire should be connected to MI4 and the other to DCM. These are wired and the appropriate programming is taken care of before leaving our facility.

The wires that come out of the orange servo cable are:

1 Ground wire
3 wires for spindle power
1 shielding ground wire
2 wires for thermistor

Please feel free to email me if you have any other wiring or programming questions on the HSD spindles that we sell.

Gordon

[evan]

My apologies to all… The road to hell is paved in good intentions. I took an even closer look and the two wires I thought were spliced together, they are actually wrapped together in shielding coming out of the heat shrink tubing on the end of the Orange servo cable. They are of a different gage than the other wires in the cable, part of my confusion. They are connected in the VFD just as Gordon reported they should be. I was not trying to make any sort of positive or negative comment on the wiring of the HSD spindle supplied by ShopBot. I am very happy with my HSD spindle and am thinking of getting a second one for my second Z. I’ll be much more careful in the future. Again my sincere apologies for any confusion I caused.

[gerald_d]

Gordon, you appear to be using thermoswitch terminology "...for a Normally.Closed. connection. If the thermistor opens... ". I am still concerned that the difference between a thermistor and a thermoswitch (klixon) has not been picked up. Another thread..

The Delta folk told me that I could not connect a thermistor directly to their drive and that I would have to get a thermistor relay to put in between. I see that some Yaskawa drives can accept a thermistor directly. (Page 75 of this manual) A properly matched resistor would have to added as well?

(Terminals M14 & DCM sound like Delta, while Evan has a Yaskawa?)

[gerald_d]

These Thermik thermistors are used by HSD. A good "thermistor relay" ensures the following:


15454.gif

I have a Siemens 3RN relay at the moment, and I see that it puts 2V and 5mW to the thermistor.

If I were worried about external bearing temperature, I could strap another thermistor on there and wire it in series with the internal one.

[gordon]

Gerald,

You are right the connections above (MI4 & DCM) are for a Delta VFD. The thermistor connections to the Yaskawa VFD are S4 and SC. As for the connecting a Colombo spindle to a Delta VFD and them not being compatible you will need to talk to PDS-Colombo about that. They wire the spindles to the Delta VFD according to their specifications, program and test them before shipping them to our customers. I will need to ask them this question directly.

This exert from the MT1073 manual is all the information I have at the moment on the "thermistor" that is installed in the HSD MT1073 spindles.

4.3 MOTOR THERMISTOR
A PTC thermistor is installed in the stator windings to monitor temperature. Electrical resistance from the thermistor
increases rapidly as it reaches trip temperature (normally 100°C or 130°C depending on the model).
The signal from the thermistor must be fed to a control device to stop the machine in order to protect the electro-spindle
from the effects of overheating.
Thermistor trip temperature depends on the model of electro-spindle. (See the relevant attachments.)
The thermistors used in these electro-spindles comply with DIN 44081-44082 standards.
Temperature – Resistance curve
according to DIN 44081/44082
Figure 1.4
Main specifications
Nominal trip temperature
TNF= from 50°C to 200°C
in steps of 10K or 5K
Characteristic values for
PTC thermistors Resistance
Measurement
voltage

[gerald_d]

S4 on Yaskawa appears to be a "digital" input and unsuitable for an analog device like a thermistor. (I don't know which Yaskawa is being used - the E7 manual (linked above) mentions "analog" inputs for a thermistor).

I have mailed you the info I got from HSD re their thermistors, but they are the typical/garden variety conforming to Euro Norm 44081/2.