Is it safe to Power the Kapex 120 REB from CT 36?

[Bugsysiegals]

[member=101]Festool USA[/member],

Is it safe or recommended to connect the Kapex 120 REB to the CT 36 on full suction versus powering it directly from a wall outlet?

I'm asking because it's unclear whether the US motor failures were believed or discovered to be from under powering them, the US electromagnetic braking system overheating the motors, etc. 

I'm powering the Kapex from the wall to be on the safe side but forgot to turn on the vacuum twice and was surrounded in MDF dust ... if it's safe to power the Kapex from the CT 36, it would be really nice to know.

 

[Bohdan]

Powering the Kapex (or anything else) from the CT doesn't limit the power to what the lable says.

What limits the power is the size of the fuse for the outlet that the CT is plugged into. The lable is based on the most likely fuse and if that power is exceeded continuously the fuse will blow.

The CT itself cannot limit the power available so if the fuse isn't popping then you don't have a problem.

 

[peter halle]

From what I have understood for years, and currently, is that it is safe. 

Peter

 

[Bugsysiegals]

Powering the Kapex (or anything else) from the CT doesn't limit the power to what the lable says.

What limits the power is the size of the fuse for the outlet that the CT is plugged into. The lable is based on the most likely fuse and if that power is exceeded continuously the fuse will blow.

The CT itself cannot limit the power available so if the fuse isn't popping then you don't have a problem.

The recommended load on a circuit shouldn't exceed 80%.  That said, you're saying if I connect the CT 36 to a 50 amp circuit breaker, I can draw 40 Amps or 4,800 Watts from the electrical port?

The CT 36 manual states a maximum of 1,200 Watts or 10 Amps can be output from the power port.  While I suspect this is underrated, I doubt it can output 40 Amps if connected to a 50 Amp circuit.  I suspect it either has internal protection or will surely burn up the internal circuits/wiring.  That said, I know some people here have connected the OF 2200 and Kapex to the Vacuum but if the vacuum only outputs "12" Amps, I wonder if this "under powering" can cause premature failure of either the vacuum or the connected tool.

 

[Bugsysiegals]

From what I have understood for years, and currently, is that it is safe. 

Peter

Thanks [member=1674]Peter Halle[/member]!

 

[aloysius]

Powering the Kapex (or anything else) from the CT doesn't limit the power to what the lable says.

What limits the power is the size of the fuse for the outlet that the CT is plugged into. The lable is based on the most likely fuse and if that power is exceeded continuously the fuse will blow.

The CT itself cannot limit the power available so if the fuse isn't popping then you don't have a problem.

So if I connect the CT 36 to a 50 amp circuit breaker I can power something from the CT 36 which consumes 40 Amps or 4,800 Watts?

That's a bit overboard.  That's a total load (including the Vac) of some 6Kw!  The cabling isn't designed for so much current.  At the very least, you'll probably overheat the spade connections in your plugs & sockets & possibly also the cable.

Worse is that you could possibly overheat & irreparably damage the auto on/off circuitry within.

Worst of all is that the excessive heat could cause a fire.

A total load of approx. 15 Amperes (@ 240 V), corrected for alternative voltages using Ohms' Law:  say 3600 Watts @ 240V or 30A/3600 Watts @ 120V would be "safe" maxima.

Total load INCLUDES the vac too, meaning that the "accessory" load connected to the CT36 should not exceed 2400W/10A @ 240V or 2400W/20A @ 120V.  Excessive loads will also invalidate your warranty.

 

[Birdhunter]

I’ve been running my Kapex through my Mini for years. No issues.

 

[Bugsysiegals]

Powering the Kapex (or anything else) from the CT doesn't limit the power to what the lable says.

What limits the power is the size of the fuse for the outlet that the CT is plugged into. The lable is based on the most likely fuse and if that power is exceeded continuously the fuse will blow.

The CT itself cannot limit the power available so if the fuse isn't popping then you don't have a problem.

So if I connect the CT 36 to a 50 amp circuit breaker I can power something from the CT 36 which consumes 40 Amps or 4,800 Watts?

That's a bit overboard.  That's a total load (including the Vac) of some 6Kw!  The cabling isn't designed for so much current.  At the very least, you'll probably overheat the spade connections in your plugs & sockets & possibly also the cable.

Worse is that you could possibly overheat & irreparably damage the auto on/off circuitry within.

Worst of all is that the excessive heat could cause a fire.

A total load of approx. 15 Amperes (@ 240 V), corrected for alternative voltages using Ohms' Law:  say 3600 Watts @ 240V or 30A/3600 Watts @ 120V would be "safe" maxima.

Total load INCLUDES the vac too, meaning that the "accessory" load connected to the CT36 should not exceed 2400W/10A @ 240V or 2400W/20A @ 120V.  Excessive loads will also invalidate your warranty.

Yes, this is excessive, and was used to draw a point ... that the vacuum has a limit which is independent of the circuit it’s on, unless of course the circuit is undersized.

 

[Bugsysiegals]

I’ve been running my Kapex through my Mini for years. No issues.

Thanks!  I’d like to think I’ve learned my lesson after forgetting twice but I’m sure there would be some future forgetfulness ... nice to know I can plug into the vacuum with confidence.

 

[ChuckM]

Such concern had been floated many many times when the motor issue was widely discussed. To be on the safe side, I use my shop vac with this so the Kapex (EB) and shop vac draw from two different outlets (15 amps each):https://www.leevalley.com/en-ca/sho...013-ivac-automatic-vacuum-switch?item=03J6210

 

[Bugsysiegals]

When I turn on my Kapex my Kill-A-Watt shows a spike of about 12-13 Amps and then maybe about 11 Amps whether plugged into the wall or CT 36.  I’m not sure what happens under load and whether under powering a motor will cause premature failure but I fly a FPV quadcopter and am familiar with how PID settings and motor braking can cause a motor to become to hot to touch resulting in premature failure.

As I recall, the motor issue was isolated to the US version of the Kapex and I recently watched a Festool Live where they said the US version had a different braking system than the rest of the world. I suspect it’s the difference in electrical voltage/phasing but it certainly made me wonder whether repetitive on/offs with the US braking module/settings causes the motors to overheat.

It’s anybody’s guess what was replaced/upgraded in the newer version but if it was the braking mechanism I suppose the original versions would only fail for those who repetitively turn them on/off to rapidly.

 

[Ron B]

Such concern had been floated many many times when the motor issue was widely discussed. To be on the safe side, I use my shop vac with this so the Kapex (EB) and shop vac draw from two different outlets (15 amps each):https://www.leevalley.com/en-ca/sho...013-ivac-automatic-vacuum-switch?item=03J6210

Chuck-that is an interesting item from LeeValley.  I recently purchased a Kapex and need to buy a vac (I am new to Festool).  I like the idea of running off of two different circuit breakers. 

 

[Birdhunter]

I have a Mini dedicated to my Kapex for many years. No issue. I treat the Kapex with respect. No issues. I keep the bag no more than 1/2 full. No issues. I never slam the
Kapex into tough heavy wood. No issues.I often take two passes through a thick board of tough wood. No issues. The Mini is plugged into a dedicated 20 amp circuit. No issues.

I have a second general purpose Mini the driver Domino machines, sanders, routers up to the 2200 with no issues.

I have a third Mini that is attached to the big SawStop overarm dust collector. No issues.

 

[Bugsysiegals]

I have a Mini dedicated to my Kapex for many years. No issue. I treat the Kapex with respect. No issues. I keep the bag no more than 1/2 full. No issues. I never slam the
Kapex into tough heavy wood. No issues.I often take two passes through a thick board of tough wood. No issues. The Mini is plugged into a dedicated 20 amp circuit. No issues.

I have a second general purpose Mini the driver Domino machines, sanders, routers up to the 2200 with no issues.

I have a third Mini that is attached to the big SawStop overarm dust collector. No issues.

Sweet, I’ll power it from the vacuum as I never force or overwork my tools either!  And it’s great to know the Mini is a capable vacuum if I’m ever looking for a smaller unit!

 

[MaineShop]

All I can offer is that I run my Kapex hard and put it away wet. It has always been through a CT except for a few cuts and have been running it daily 5 days a week for at least 5 or 6 years. No issues yet. Semi- related, on jobsites when we use to do framing there are a lot of times we would be working off a generator and sometimes too many things going at once and that would cause some funky power drops, never with my kapex, as I was not using one then. But in general never burned up any tool because of that, table saws in particular would take a beating on that when you were ripping something down and all of a sudden the compressor kicks on mid cut. I feel the kapex has better motors then those old jobsite tools.

 

[ChuckM]

It’s anybody’s guess what was replaced/upgraded in the newer version but if it was the braking mechanism I suppose the original versions would only fail for those who repetitively turn them on/off to rapidly.

Indeed. It's anybody's guess. Festool only acknowledged the existence of a motor problem after producing an "improved" motor which is now used in the REB.

 

[Bugsysiegals]

It’s anybody’s guess what was replaced/upgraded in the newer version but if it was the braking mechanism I suppose the original versions would only fail for those who repetitively turn them on/off to rapidly.

Indeed. It's anybody's guess. Festool only acknowledged the existence of a motor problem after producing an "improved" motor which is now used in the REB.

I’d also heard suspicions it was people running from generators or long extension cords but that’s not me so I’m fairly happy to know I should experience a nice long life of my Kapex with no regrets.