What can I connect to CT36 AC?

[Lazy]

Thanks for that info. Very helpful.

 

[Lazy]

I asked the folks at fluke if my 177 multimeter's min/max function samples often enough to capture a startup event. Here's what they said:

"The Fluke 177 Min/Max function is too slow to capture a start-up event. Clampmeters with an Inrush function like the 374, 375 or 376 are a better choice for this."

I'm not going to buy one at this time. I've been spending too much money lately. However, I tested the min max function on my 177 and it beeps every time it replaces the min or max values with a new one. It was beeping like a machine gun so it may miss the peak but I would probably get a good idea of Max amp at startup especially if the test was repeated several times making it more probable that it would sample at the peak. Considering all this, I may not splurge on an amp clamp right now but it is on my wish list along with a fluke 289. Maybe after I sell the house I'm remodeling.

I do however want to warn people that are considering connecting a table saw without a soft start function directly to the Festool CT that this may not be a good idea. My experience tells me that it will draw too many amps at startup or even during heavy continouse use. I just wish it was easier for me to prove it without turning my pockets inside out for more electrical equipment.

 

[Holmz]

You probably really want to know steady state anyhow.
If the breaker is not throwing it must be low, and the soft start implies some time over which the energy is going in.

 

[Lazy]

The problem is my ridgid table saw sounds like a transformer cranking up be cause it does NOT have soft start. You know...... that sound that vibrates your teeth. I'm just gonna put it on a separate breaker until I have time to test. I can probably choke the saw on rough cut lumber and borrow my friend's amp clamp. I'm gonna build the test extension cord because this isn't the first time I wanted this kind of data and had no easy way to get answers.

 

[Lazy]

OK. I don't have to make a test line. They sell line splitters cheap.

 

[Bohdan]

Have an electrician fit your saw with a contactor that can be used to fire up the CT on a separate breaker whenever the saw is on. This can also be fitted with a bypass switch to enable the CT to work independently.

 

[Lazy]

I want this to be portable so dealing with contactors and one of those doorbell size transformers to operate it may be more trouble than it's worth. I guess I could mount a contactor, transformer, and an extra cord and outlet on the table saw. That way I could unload the table saw and plug it into two different outlets that are on different breakers. Then plug the dust extractor into the table saw. Kind of a neat idea but I would probably just plug the dust extractor on a separate outlet and use a remote switch instead of adding the extra cord and whatnot to the portable table saw.

 

[Bohdan]

I want this to be portable so dealing with contactors and one of those doorbell size transformers to operate it may be more trouble than it's worth.

You don't need a transformer as a line voltage contactor connected in parallel with the motor will do the switching.

 

[Lazy]

On another note.....I've been thinking about inrush current and was thinking that since breakers are made to handle inrush without tripping that the dust extractor outlet and wiring can probably handle it as well.

Just like Holmz said, the steadier current probably matters more.

So here's my experiment plan....
I ordered a current clamp to use with my fluke and will measure the max current under load (while pushing wood) that the fluke can read with the sampling frequency it has.

 

[Lazy]

[/quote]
You don't need a transformer as a line voltage contactor connected in parallel with the motor will do the switching.
[/quote]

Well that simplifies it some. I was thinking of low voltage contactors.

 

[Lazy]

This is what I have observed messing around with my new amp clamp. Note that the max values are not inrush current because that amperage would be much higher but arguably less important. These measurements were taken with a Fluke 177 multimeter and Fluke i410 amp clamp.

CT 36 AC
All measurements taken with no hose attached, with festool blast gate installed, auto clean turned off, with a clean filter.

Blast gate open and set to full power:
11 amps continuous
12 amps at start

Blast gate open and set to minimum power:
7.7 amps continuous
8 amps at start

Blast gate closed and set to full power:
6.9 amps continuous
11.7 amps at start

Blast gate closed and set to minimum power:
5.4 amps continuous
7.8 amps at start

Blast gate closed engage auto-clean function:
13.3 amps max

I'm about to test some other stuff now. It seems like the unit requires less amperage when the blast gate is shut. That is probably because the motor/fan is running in a partial vacuum.

 

[Lazy]

I tested my table saw.

Ridgid R4513 10” portable table saw:
24 amps at start
5.7 amps continuous with no load

18.2 amps under load pushing cedar much harder than usual. I would generally never push this hard but wanted to see what was possible. I'm sure I could have bogged it down further and pulled more amps but didn't see the point and I like to keep my toys in working order.

10-14 amps under load pushing cedar like I'm in a hurry but these are pretty normal conditions.

 

[Bohdan]

What is the current draw with hose connected and blast gate open? Which hose do you have?

Do you have a filter bag in the vac or are you using it with a plastic bag and using the auto clean feature.

 

[Lazy]

I'll need to answer those questions later because I have put up my equipment for the night.

All of the tests so far were done with no bag at all. I have both a 36mm 11.5 foot planex hose and a 27mm 3.5m AS hose that came with my rotex 125.

I will say that i believe the difference in power/amp draw would be marginal with larger diameter hoses unless they are super long. The difference may be more noticeable with the 27mm hose though. I'll go into more depth tomorrow if I have time.

 

[Bohdan]

For use with the rotex you need to fit a bag and HEPA filter as the self clean filter allows the small particles thru and without a bag you will clog your HEPA filter.

 

[Lazy]

The main reason I did this was to show that connecting a table saw (rated at 15amps with no soft start) to a CT 36 AC,  could easily trigger a 20 amp circuit breaker or possibly put our dust extractors at risk. I would hope that Festool beefed up the internal circuitry in the dust extractor and rely on the circuit breaker to be the weak point in the circuit but there's no way I can be sure without confirmation from festool or taking it apart. I'm not willing to go quite that far.

Bohdan, I want to thank you for your contactor idea. I did wire up a contactor. I put it in the smallest box possible with three short pigtails sticking out. One for the coil power, another for input power from a separate circuit, and one for output to my shop vac or whatever I want to run simultaneously. I tapped into my table saw power on the motor side of the switch housing and put a small pigtail on that. Each pigtail has a male or female 3-prong standard connection for convenience. We used this setup on site yesterday and today. It worked very well. So thanks again for your input. I appreciate it very much.

 

[Lazy]

For use with the rotex you need to fit a bag and HEPA filter as the self clean filter allows the small particles thru and without a bag you will clog your HEPA filter.

I don't think the CT 36 AC has HEPA installed.

 

[Holmz]

...
Bohdan, I want to thank you for your contactor idea. I did wire up a contactor. I put it in the smallest box possible with three short pigtails sticking out. One for the coil power, another for input power from a separate circuit, and one for output to my shop vac or whatever I want to run simultaneously. I tapped into my table saw power on the motor side of the switch housing and put a small pigtail on that. Each pigtail has a male or female 3-prong standard connection for convenience. We used this setup on site yesterday and today. It worked very well. So thanks again for your input. I appreciate it very much.

A schematic could be helpful, and a part number for the contactor deal.

 

[Lazy]

Sure. I can take some pictures and provide more info tomorrow. I used a 2-pole contactor and put the hot on one pole and the neutral on the other. I couldn't easily find a single pole contactor with a coil that operates on 110/120v.

I could have only used one pole for the hot and kept both the neutral and ground continuous but it was easier to break both the neutral and the hot to cram this into the box.

 

[Bohdan]

No it doesn't come with one as it is designed for use with plaster, which is a coarse but 'sticky' dust, but if you are going to use it with wood then I suggest that it would be really worth the added cost to get one and only use it with a bag.