Installing 12 VFDs in one control cabinet

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Fallriverbryan said:
2000 cfm running constantly?
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I would. We did have one customer who specified that the fans stopped after the drive stopped - there was a run on timer to delay the drop out. Energy efficiency was the justification cited but the energy consumption of the fans was tiny compared to the drive ratings. In any case, the drives we supplied were almost all on continuous production processes so the fans would hardly ever be off.
 
Besoeker said:
I would. We did have one customer who specified that the fans stopped after the drive stopped - there was a run on timer to delay the drop out. Energy efficiency was the justification cited but the energy consumption of the fans was tiny compared to the drive ratings. In any case, the drives we supplied were almost all on continuous production processes so the fans would hardly ever be off.
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the best reason for a thermostat is to save the fans. most fans don't last real long. better to only run them as needed. it also helps with not having to clean the filters as much. the less the fans run the less often the filters have to be cleaned.
 
petersonra said:
the best reason for a thermostat is to save the fans. most fans don't last real long. better to only run them as needed. it also helps with not having to clean the filters as much. the less the fans run the less often the filters have to be cleaned.
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Well, yes. Fair points. But then you need to decide where to fit the thermostats. The critically temperature sensitive components are usually the power semiconductors and most reasonably recent drives have temperature monitoring for that. I don't know whether one could slave off that but it usually initiates a shut down/trip.

We used to put in air flow switches to detect cooling fan faults and thermal switches on the heatsinks.
 
I have seen cabinets with a small fan that runs whenever a drive is on and larger fans that run on a thermostat.

Many drives come with fans on the heat sinks.

If you want to get fancy you could control the fans via your PLC system if you have one.

I don't think there is much of an issue with finding an appropriate spot for the thermostat(s). Just mount it/them a foot or so above the drives.

A lot of modern drives have a heat sink option available where the heat sink can be mounted through the back of a cabinet so the heat does not go inside the cabinet and have to be vented or cooled.

On of our customers has us put what they call a stirring fan in every cabinet. It is a DIN rail mounted fan that just moves a little bit of air around inside the cabinet.

There are a lot of things you can do to deal with the heat.
 
heating up

heating up

Thanks for the input. Controls will be a retro fit at a later date but is a good idea to use that for speed control and on/off. . Makes sense to limit fans operation as a maintenance issue. Filters wont get changed till something happens.
 
petersonra said:
I have seen cabinets with a small fan that runs whenever a drive is on and larger fans that run on a thermostat.

Many drives come with fans on the heat sinks.

If you want to get fancy you could control the fans via your PLC system if you have one.

I don't think there is much of an issue with finding an appropriate spot for the thermostat(s). Just mount it/them a foot or so above the drives.

A lot of modern drives have a heat sink option available where the heat sink can be mounted through the back of a cabinet so the heat does not go inside the cabinet and have to be vented or cooled.

On of our customers has us put what they call a stirring fan in every cabinet. It is a DIN rail mounted fan that just moves a little bit of air around inside the cabinet.

There are a lot of things you can do to deal with the heat.
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Yes, there a lot of things one can do.
You still need to get the heat out of the enclosure whatever. On ventilated drives, I simply calculated the heat loss in kW and selected a fan (or fans) that would shift the required volume of air to maintain a low rise - normally 10C or less.

I think that's what the OP needs to do.
 
Fans are fine if you have a CLEAN, DRY environment. Some of the most spectacular drive failures I've seen have been the result of a severe buildup of dirt and airborne oil creating a "crust" over all things heat sink related, or moisture pulled in by the fans giving a nice path to ground for the power components.

Filters are fine if you have a RIGOROUS maintenance program to periodically change / clean them whether someone thinks they need it or not. Last month and the month before I visited two sites where users were complaining of drives constantly tripping on Over Temperature, only to find filters so clogged they were in effect, sealed enclosures.

Bottom line, don't check your common sense at the door in favor of economic savings, it usually ends badly and costs more later.
 
Jraef said:
Fans are fine if you have a CLEAN, DRY environment. Some of the most spectacular drive failures I've seen have been the result of a severe buildup of dirt and airborne oil creating a "crust" over all things heat sink related, or moisture pulled in by the fans giving a nice path to ground for the power components.

Filters are fine if you have a RIGOROUS maintenance program to periodically change / clean them whether someone thinks they need it or not. Last month and the month before I visited two sites where users were complaining of drives constantly tripping on Over Temperature, only to find filters so clogged they were in effect, sealed enclosures.

Bottom line, don't check your common sense at the door in favor of economic savings, it usually ends badly and costs more later.
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I don't disagree with that. Much of what I did was in paper mills, cement works, steel mills and some sewage treatment works.
One of the major aspects of such projects was making sure that the drives were in a clean, dry environment. The other is strictly adhered to maintenance programmes. Fans and filters are cheap compared to the down time of a paper machine. A paper mill in Kent had a notice in the electrician's shop.
"Down time costs £4,700 per hour. "
That was in 1979..........
 
We mostly use AC units and proper clearance above and below the drives. My concern is the ACs are basically replacing the air on one side of the cabinet
especially on double door or larger. The drives all have fans so maybe that's enough circulation. Seems a fan(s) blowing across might be better and
cheaper. An AC unit for a electrical cabinet costs as much as the cooling for my house.
 
The irrigation company I worked for in the 90's used a lot of Robicon vfd's in the 250-600 hp range, until we ran into harmonics problems.

we would usually build an enclosure that went over the entire Robicon 3R panel. Our add on enclose was about a foot larger in all dimensions than the panel. It had a heat pump on it with a thermostat.
 
After the Robicon, we went to Unico drives. In my area, Yaskawa drives are probable the most common drive in agricultural irrigation for centrifugal and turbine pumps.

all the yaskawa drive I've seen are in 3R enclosures with a thermostatically controlled fan and foam filters at the vents,
 
Besoeker said:
I don't disagree with that. Much of what I did was in paper mills, cement works, steel mills and some sewage treatment works.
One of the major aspects of such projects was making sure that the drives were in a clean, dry environment. The other is strictly adhered to maintenance programmes. Fans and filters are cheap compared to the down time of a paper machine. A paper mill in Kent had a notice in the electrician's shop.
"Down time costs £4,700 per hour. "
That was in 1979..........
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A lot of car plants you can lose a car a minute if you go down.
 
Dzboyce said:
After the Robicon, we went to Unico drives. In my area, Yaskawa drives are probable the most common drive in agricultural irrigation for centrifugal and turbine pumps.

all the yaskawa drive I've seen are in 3R enclosures with a thermostatically controlled fan and foam filters at the vents,
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Yaskawa maybe the cheapest Drive available
 
petersonra said:
Yaskawa maybe the cheapest Drive available
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No, there are dirt cheap no-name knockoff drives coming from China and sold on FleaBay and Amazon now that are the worst things I have ever seen. Bad solder joints, questionable components, no UL listing, apparently zero quality control and manuals that have been translated from Chinese by 2nd graders. If people keep buying them because the price is so low, the bad experiences they have threaten the reputation of the entire industry.
 
petersonra said:
A lot of car plants you can lose a car a minute if you go down.
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It's hard to imagine that a new car rolls off the line every minute, until you see it in action. Our local old GM plant is now the Tesla plant and they are not yet up to that rate, but when they made Pontiacs and Chevys there, it was. Every little hiccup becomes a big fat hairy deal...
 
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