Can CT Vacs safely run under blocked suction?

[Bob D.]

The CT SYS is a little different than the others in this regard.  First, all the other CT vacuums do have bypass cooling, which is essentially a secondary fan that pulls air through the motor area, which keeps the vacuum cool if it were to clog.

In the case of the CT SYS, there is a slightly different set-up.  If the hose becomes clogged, a bypass valve will open.  You can actually hear it.  This still provides the protection from overheating, it is just a different design than the standard CT.

The bypass valve is something the central vac system in the house has, and I have often thought I should add it to my dust collection system in the shop. For the house vac it's great because it prevents those times where your vacuum latches on to something like a drape or piece of cloth and it seems the only way you can free it up is to shut the vac off. The bypass valve is adjustable.

I bring this up because I have used my whole house central vac with a Dust Deputy when working around the house in place of removing the CT36 from the shop and dragging it around with me. The house vac has plenty of power, is a HEPA vac, and is located in the garage so all the noise is outside the house. I made up some adapters so I can run just about any handheld power tool I have off this setup, including my DeWalt cordless mitersaw and DeWalt track saw before I got the TSC55. No sawdust makes it out to the vacuum dust bin, it's all captured in the Dust Deputy's 5 gallon bucket.

 

[Coen]

Normal home vacuum cleaners don't have a separate air channel for cooling. The CT's (except the -SYS) do have that channel. You can check that for yourself; when you block the hose, there is still plenty of airflow coming out.

The different design of the CT SYS would also mean it's maximum underpressure is more limited.

 

[Brice Burrell]

Normal home vacuum cleaners don't have a separate air channel for cooling. The CT's (except the -SYS) do have that channel. You can check that for yourself; when you block the hose, there is still plenty of airflow coming out.

The different design of the CT SYS would also mean it's maximum underpressure is more limited.

Vacuums, for the most part, run on universal motors.  Almost all universal motors have a cooling fan on top. Now, with the exceptions put aside, we can say pretty much all vacs have a separate cooling fan, and do not use the vacuum air to cool the motor.  So, yes, your house hold vac does have separate air channel for cooling.  And so does any house hold appliance with a universal motor.

One exception is the CT Sys.  It doesn't have a cooling fan on the motor, that I know of.  Looking at pictures it looks like the vacuum air does cool the motor, but I can't tell for sure without seeing one in person. 

   

 

[Bob D.]

Normal home vacuum cleaners don't have a separate air channel for cooling. The CT's (except the -SYS) do have that channel. You can check that for yourself; when you block the hose, there is still plenty of airflow coming out.

The different design of the CT SYS would also mean it's maximum underpressure is more limited.

I was not referring to a 'normal home vacuum cleaner', I was talking about a whole house central vacuum system that is hard-piped throughout the house. The vacuum and debris canister resides in the garage, all you have in the house is the hose and attachments. All the dust and noise stays out in the garage. So, in my basement shop I tapped into the 2" PVC pipe for the central vac and have an outlet I can use with a Dust Deputy inline to catch all the sawdust and chips and the central vac provides the suction. I have no noise in the shop to bother me or anyone in the house. I use my basement shop in the dead of winter when it is too cold to work in the garage shop. The space in the garage dedicated to the shop is 24'x24', insulated and I have a heat pump for heat but that is only effective down to 38°F. When the temp drops to freezing or lower it can't keep up.