Re: Huanyang VFD, activate relay when running below predefined RPM?
Quote:
Originally Posted by
jhovel
What about a thermostat on the spindle itself, switching the fan on only when needed - irrespective of rpm?
Cheers, Joe
I like this idea the best. The fan is needed when temperatures rise, not simply because of RPM. I haven't looked for a solution, but it seems like it might be simpler. There might be a ready made solution to control an attic fan.
Steve
Re: Huanyang VFD, activate relay when running below predefined RPM?
An attic fan thermostat may have too much hysteresis (difference between switching on and off).
I suspect that one would need a thermostat that won't allow the temperature to change much at all, because an air cooled spindle can heat up very fast indeed, compared to a water cooled spindle.
Cheers, Joe
Re: Huanyang VFD, activate relay when running below predefined RPM?
Quote:
Originally Posted by
mactec54
I believe he is trying to run his spindle too slow, for a air cooled spindle, and this is where the problem is
That's the exact point of this thread. I try to run air cooled spindle at speeds that are usualy only achieved by water cooled spindles. Only problem is the cooling fan is on the spindle shaft, so at low RPM it does not provide sufficient airflow. That's usualy solved by water cooling. But i just want to install external fan, that will provide airflow similar to airflow of internal fan at full RPMs, because for me it seems more practical than handle all the water plumbing.
Quote:
Originally Posted by
mactec54
A thermostat would be a good approach
I guess so. But i am not sure if it's enough to put the thermistor (temperature probe of thermostat) directly at spindle body. Would that be enough? I am affraid, that motor windings will reach temperature faster than the body of spindle. I am not sure how well it conducts the heat from windings to body.
3 Attachment(s)
Re: Huanyang VFD, activate relay when running below predefined RPM?
Quote:
Originally Posted by
phucrobusl
I guess so. But i am not sure if it's enough to put the thermistor (temperature probe of thermostat) directly at spindle body. Would that be enough? I am affraid, that motor windings will reach temperature faster than the body of spindle. I am not sure how well it conducts the heat from windings to body.
That's is what I thought as well the winding will get to hot before the thermistor would turn on, if it was mounted externally, normally thermistors are mounted inside the motor, and are normally used to shut the motor down when it over heats
By correct positioning, thermistors can be located close to the thermally critical areas, or hot-spots, of the winding, where they closely track the copper temperature with a certain time lag, depending on the size of the thermistors and how well they are installed in the winding.
The Time lag may be to great in your case
The rated response temperature (RRT) of the thermistor is correctly selected for the class of insulation used on the winding. the thermistors are correctly located close to the thermally critical areas.
There is a low thermal resistance between the winding and the PTC thermistor. This depends on the electrical insulation between the winding and the thermistor. Since thermistors need to be isolated from high voltages, it is more difficult to achieve a low heat transfer resistance in HV motors, which have greater insulation thickness.
In these cases, to achieve complete protection, thermistors should be used in combination with electronic motor protection relays, which monitor the primary current drawn by the motor. this is where it gets even more complicated
So in reality it may not be as practical to use a thermistor, unless you are able to place and use them correctly
Did you try the Parameters setup I suggested
Re: Huanyang VFD, activate relay when running below predefined RPM?
Quote:
Originally Posted by
mactec54
Did you try the Parameters setup I suggested
PD052=07 (uniform frequency reach 2)
PD061=150Hz or adjust to get to the 8,000 rpm (uniform frequency 2)
PD062= the frequency range that you want it to be on or off, this may need to be set at max of 10Hz if to low it may cause switching on/off rapidly as the spindle RPMs will fluctuate, this may of been what you where seeing with the relays before
I just tried this and it acts basicaly same as with PD052=06; PD060=150, which i tried initialy. Only difference is that it acts on ramp down instead of ramp up. It just switches the relay for a while when stopping, instead of keeping it that way when running on 100 RPM.
Re: Huanyang VFD, activate relay when running below predefined RPM?
I think i've just partialy solved the issue by doing few more tests. Problem is that VFD documentation is not accurate. Documentation on PD052 options says this:
06: Uniform Frequency 1 Reach: The contact will act when the output frequency of the inverterreaches the designated frequency (PD060).
07: Uniform Frequency 2 reach: The contact will act when the output frequency of the inverterreaches the designated frequency (PD061).
08: In Accel: The contact will act when the inverter is in ramp-up.
09: In Decel: The contact will act when the inverter is in ramp-down.
But i've found that in reality these are implemented other way round:
06: In Accel: The contact will act when the inverter is in ramp-up.
07: In Decel: The contact will act when the inverter is in ramp-down.
08: Uniform Frequency 1 Reach: The contact will act when the output frequency of the inverter reaches the designated frequency (PD060).
09: Uniform Frequency 2 reach: The contact will act when the output frequency of the inverter reaches the designated frequency (PD061).
Documentation level: Chinese :D
So this somewhat solves my problem. Now i can set PD060 to detect whether spindle runs over 8000 RPMs. However i can't tell if it's running under 8000 RPMs or is stopped completely. But that can be probably solved by adding few more relays (if i don't find easier way to do it).
1 Attachment(s)
Re: Huanyang VFD, activate relay when running below predefined RPM?
Quote:
Originally Posted by
phucrobusl
I think i've just partialy solved the issue by doing few more tests. Problem is that VFD documentation is not accurate. Documentation on PD052 options says this:
06: Uniform Frequency 1 Reach: The contact will act when the output frequency of the inverterreaches the designated frequency (PD060).
07: Uniform Frequency 2 reach: The contact will act when the output frequency of the inverterreaches the designated frequency (PD061).
08: In Accel: The contact will act when the inverter is in ramp-up.
09: In Decel: The contact will act when the inverter is in ramp-down.
But i've found that in reality these are implemented other way round:
06: In Accel: The contact will act when the inverter is in ramp-up.
07: In Decel: The contact will act when the inverter is in ramp-down.
08: Uniform Frequency 1 Reach: The contact will act when the output frequency of the inverter reaches the designated frequency (PD060).
09: Uniform Frequency 2 reach: The contact will act when the output frequency of the inverter reaches the designated frequency (PD061).
So this somewhat solves my problem. Now i can set PD060 to detect whether spindle runs over 8000 RPMs. However i can't tell if it's running under 8000 RPMs or is stopped completely. But that can be probably solved by adding few more relays (if i don't find easier way to do it).
There is nothing wrong with the documentation, its having the right documentation
It would depend on what model VFD you have as to which way the Parameters are set, there are many variations not all manuals are correct for the VFD Drive you may have, You have to get the right manual that suits your VFD, what you are saying is correct, and not the other way round, here is a snip from one of there manuals
Re: Huanyang VFD, activate relay when running below predefined RPM?
Quote:
Originally Posted by
mactec54
You have to get the right manual that suits your VFD, what you are saying is correct, and not the other way round
How do i tell which Huanyang VFD model i have? Ebay seller does not provide any exact details and i have troubles figuring this out by myself. Is that written somehere on the unit?
Re: Huanyang VFD, activate relay when running below predefined RPM?
So if you set 08 to 8000 RPM, and 09 to say 100 RPM (lower than what you would ever run it at but high enough that it wouldn't be on at 0 speed,) would it connect one output at >= 100 RPM, then another output when >= 8000?
If so you can do some relay logic, probably need 2 relays. If output A is for 8000 RPM and B is for 100 RPM, you need !A || B. Which with relays you should be able to implement with 1 NC or dual throw relay and 1 NO or dual throw relay. A would be wired to the coil of the NC relay, and the output of the NC relay would be wired in series with output B to the coil of the NO relay (with the NO Contacts wired to the fan.)