Blower Motor Tripping on Powder Booth

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duttonbrown

Lighting Designer
Location
Minneapolis, MN, USA
Occupation
Product Engineer, Lighting Designer
Hello,
Working to install a powder coating booth (http://www.colo-group.com/closed-powder-coating-booth-15241932163728183.html) which shipped with a fan + blower. The unit is assembled and ready for use, but when I switch the fan on, it starts to ramp up and then trips the breaker inside the panel attached to the booth. It seems the fan draws too much current and cuts off before the fan gets up to speed.
2022-08-29_13-32-22.jpg20220829_182821000_iOS.jpg

I spoke to the manufacturer about this but they have ghosted me, so I'm unsure if the equipment is rated to work together or if something is defective. May I kindly ask for some advice about whether these items should work together?

Here's the motor info on the blower. I notice rated current is 13.7A.
fan-blower-specs-colo-1517-1.jpg

Here's a photo inside the control box. On the TENGEN, I moved the slider left over past 13A, but it still trips.
IMG_3456.JPG

Here's a video with sound of what happens each time. Listen to hear the fan start to spin and then it trips.

Any ideas about what may be the issue? I noticed the fan blades inside are a little bent too, but I'm not sure that'd cause it to draw so much extra current.
I really appreciate any help.
 
duttonbrown said:
Hello,
Working to install a powder coating booth (http://www.colo-group.com/closed-powder-coating-booth-15241932163728183.html) which shipped with a fan + blower. The unit is assembled and ready for use, but when I switch the fan on, it starts to ramp up and then trips the breaker inside the panel attached to the booth. It seems the fan draws too much current and cuts off before the fan gets up to speed.
View attachment 2561962View attachment 2561960

I spoke to the manufacturer about this but they have ghosted me, so I'm unsure if the equipment is rated to work together or if something is defective. May I kindly ask for some advice about whether these items should work together?

Here's the motor info on the blower. I notice rated current is 13.7A.
View attachment 2561959

Here's a photo inside the control box. On the TENGEN, I moved the slider left over past 13A, but it still trips.
View attachment 2561963

Here's a video with sound of what happens each time. Listen to hear the fan start to spin and then it trips.

Any ideas about what may be the issue? I noticed the fan blades inside are a little bent too, but I'm not sure that'd cause it to draw so much extra current.
I really appreciate any help.
Click to expand...
You might have to close everything up so the fan only draws air from inside the machine. I had this happen on a 4160 Volt, 450 hp oven fan that took too long to ramp up because the doors weren't closed and it was moving too much air.
 
We need your occupation filled in, and if not an electrician how you are related to the electrical field. Send msg to any moderator along with link to this post
 
You have several things working against you.
1) It’s a 50 HZ motor so it’s trying to run 20% faster than the machine was designed for (presuming you’re in the US running on 60HZ).
2) The motor is rated 220V/50HZ, so if you’re running 240V/60HZ, the V/HZ ratio is low.
3) Presuming picture 2 is you’re actual installation, there’s no ducting on the discharge. The unit is probably designed to have some level of static pressure provided by the ducting, which would decrease the flow and required HP.
 
retirede said:
You have several things working against you.
1) It’s a 50 HZ motor so it’s trying to run 20% faster than the machine was designed for (presuming you’re in the US running on 60HZ).
2) The motor is rated 220V/50HZ, so if you’re running 240V/60HZ, the V/HZ ratio is low.
3) Presuming picture 2 is you’re actual installation, there’s no ducting on the discharge. The unit is probably designed to have some level of static pressure provided by the ducting, which would decrease the flow and required HP.
Click to expand...
Item 1 and 3 ar the biggest issues. 20% faster speed is a lot more air, and the more air the more HP.

Best bet is to find a way to start up the fan with the discharge at least partially closed. That should lower the required HP because there will be less air flow. Maybe a piece of plywood over the flanged outlet.
 
Another point not yet mentioned is the starter wiring. IEC style starters have differential current sensing in the overload relay. All 3 poles need to have the same relative current flowing to prevent nuisance tripping.

That starter appears to be wired on only two of the three poles, causing it to quickly trip as if the motor is single phasing.

Rewire the starter and block off half of the output and it will likely run a little longer than it currently is. A backward incline blower will move air in either direction of rotation, so check the motor to ensure that it is running in the correct rotation direction.
 
retirede said:
That’s a good point. Chances are the 3 phase OL relay is sensitive to phase loss. One of the leads should be routed through the unused pole.
Click to expand...
I was actually pointing out the misspelled word.

Look closely at the way the contactor and overload relay is wired. Doesn't even look like it could work that way unless there's some kind of a jumper that you can't see.
 
Is there a damper on the inlet? Without it, the motor is trying to start under maximum load. Choke the inlet until motor is up to speed then open the damper.
 
After looking at the specs, I’m 99% sure he problem is that the 3 phase OL relay is not properly wired for use with a single phase motor.
The standard unit comes with a 3 phase motor so this was special ordered single phase. They changed to motor, but not how the OL is wired.
There could be additional issues due to the 50HZ motor that will be discovered once the OLs are wired properly.
 
Add a capacitor in line to increase power factor and lower current draw? Check spin motor by hand to check resistance or binding - power off. Check current draw with inductive clamp during start up compared to motor locked current specs? Can blades be removed to lower drag and see if motor can run without blade load?
 
retirede said:
There could be additional issues due to the 50HZ motor that will be discovered once the OLs are wired properly.
Click to expand...
Not could be, are.

Fan moving at 120% speed requires 173% (1.203) the amount of power from the motor. If we assume the fan needed 2.2kW at 50Hz, it will need 3.8kW at 60Hz, but the motor is only rated for 2.2kW. The single phase on a 3 phase OL relay exacerbates this situation, but the root cause is the physics. As Bob said, choking down the flow can compensate for the physics, then you will need to just change the OL wiring.
 
Jraef said:
Not could be, are.

Fan moving at 120% speed requires 173% (1.203) the amount of power from the motor. If we assume the fan needed 2.2kW at 50Hz, it will need 3.8kW at 60Hz, but the motor is only rated for 2.2kW. The single phase on a 3 phase OL relay exacerbates this situation, but the root cause is the physics. As Bob said, choking down the flow can compensate for the physics, then you will need to just change the OL wiring.
Click to expand...

Agreed. I covered (most of) that in post 4.
 
Little Bill said:
How should the OL be wired?
Click to expand...

It’s a 3 phase OL relay, but it looks like the single phase motor conductors only use 2 of the 3 poles. These OLs are designed to detect phase loss, so when using on single phase, one of the motor conductors needs to be routed through 2 of the poles so that all 3 poles of the OL see motor current.
 
retirede said:
It’s a 3 phase OL relay, but it looks like the single phase motor conductors only use 2 of the 3 poles. These OLs are designed to detect phase loss, so when using on single phase, one of the motor conductors needs to be routed through 2 of the poles so that all 3 poles of the OL see motor current.
Click to expand...
Gotcha!
 
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