2 unit DC ??????

[cecil dean]

Has anyone connected 2 DC unit to the same system? I have 2, 1 1/2 hp units now but only one is connected to my DC system. It works OK but when the edge and/or drum sanders are on I need more flow. I was thinking that if I hooked the other unit to my system then when I needed additional flow I could turn on the additional unit. I have around 80 ft of 4 inch pipe rounding in the shop. Not up on airflow or vacuum for shop air.

[jack forsberg]

might work but i would tie them in at different spots in the system that were closest to CFM hungry machines.

[Thomas Hotchkin]

Cecil
Try this .sawmillcreek.org/showthread.php?136395-Can-I-run-2-DC-s-in-series&highlight=duel+dust+collectors Tom

[Myk Rian]

This works
http://sawmillcreek.org/showthread.php?136395

[Judson Green]

I did this only to test. Ran them with no bags, filters and only enough piping to connect them. Used a amp meter and discovered that both of them were over rated amperage. I suppose if you were one to boost a long run maybe. But really don't think this would be a good idea. You will end up using more electricity and possibly burning up one or both motors. You'd be better off selling both and purchasing a unit better sized for you're needs. I think Bill Pentz has something about this on his site.

[Erik Christensen]

Judson - running your DC units with no bags/filters/piping is what made them over draw. I know it sounds counter intuitive but running an induction motor/air impeller with no flow resistance will result in maximum load (other than the short duration current draw on startup). A DustCollector draws current in proportion to load and load for a DC is linked to CFM of air movement not to flow restrictions - your test was with zero restrictions, therefore max CFM and a correspondingly max current draw. Try your test again with filters/bags/piping and observe how the current is reduced. Adding a 2nd DC to an existing system will reduce the CFM through the original DC and therefore cause a drop in motor current to the original DC. The degree to which load is balenced is solely determined by how evenly the flow losses are balanced between the 2 systems (assuming the 2 DC's have similar fan curves).

[Jeff Duncan]

A couple quick thoughts that aren't a direct answer, but may help your situation.....

1st) dust producing machines are hard for single stage collectors to keep up with. Even if you have enough cfm's to start, the filters clog and reduce their effectiveness fairly quickly. Ideally you want either a cyclone or an alternative way (baffle?) to separate some of the fines before they hit your filters.

2nd) 80' of 4" duct is killing your airflow. Simply put that's way too much small diameter duct. If your collectors have a 6" input you can help your performance by using 6" duct and 4" drops. Even if you increase the size of your collector your going to hit the limit for airflow through that small diameter duct, so will still not get the best performance.

last point, if you don't want to increase your duct diameter to allow for greater flow, you may want to then consider splitting your shop into 2 systems. You could cut your run length in half which would increase the effectiveness of both ends. I would argue 40' of 4" duct is still too much but it will be better than 80';)

good luck,
JeffD

[Judson Green]

A couple quick thoughts that aren't a direct answer, but may help your situation.....

1st) dust producing machines are hard for single stage collectors to keep up with. Even if you have enough cfm's to start, the filters clog and reduce their effectiveness fairly quickly. Ideally you want either a cyclone or an alternative way (baffle?) to separate some of the fines before they hit your filters.

2nd) 80' of 4" duct is killing your airflow. Simply put that's way too much small diameter duct. If your collectors have a 6" input you can help your performance by using 6" duct and 4" drops. Even if you increase the size of your collector your going to hit the limit for airflow through that small diameter duct, so will still not get the best performance.

last point, if you don't want to increase your duct diameter to allow for greater flow, you may want to then consider splitting your shop into 2 systems. You could cut your run length in half which would increase the effectiveness of both ends. I would argue 40' of 4" duct is still too much but it will be better than 80';)

good luck,
JeffD

Yes. Very good recommendation.

[cecil dean]

Thank every one, I think that I will increase the main duct to 6" and bypass the filter by going thru the wall to vent the fine dust. I have a inline container to catch the large material. The main problem I think I might have is the intake side of my fan is 4". If I run 6" to the intake and then reduce it will that be a problem?

[Jim Neeley]

Thank every one, I think that I will increase the main duct to 6" and bypass the filter by going thru the wall to vent the fine dust. I have a inline container to catch the large material. The main problem I think I might have is the intake side of my fan is 4". If I run 6" to the intake and then reduce it will that be a problem?

Once you knock out the large material, one option is to install a 6x4x4 wye (true wye like the ones that come with some dust collectors for flow going the other way) and put one DC on each 4" branch of the wye and the 6" to your inline container.

You'd still want to check your amperage draw to ensure you aren't overloading the motors.

Just one option.. that would require caution in implementation.

Jim

[Michael W. Clark]

Once you knock out the large material, one option is to install a 6x4x4 wye (true wye like the ones that come with some dust collectors for flow going the other way) and put one DC on each 4" branch of the wye and the 6" to your inline container.

You'd still want to check your amperage draw to ensure you aren't overloading the motors.

Just one option.. that would require caution in implementation.

Jim

Running the fans in parrallel like this will double the flow and would probably be very good for the 6" duct.

If you put the fans in series, you add pressure capability, but not as much flow. You need the flow for dust collection.

[Todd Kinsfather]

Cecil are you sure you only have a 4" intake on your 1-1/2 HP DC's?? I know some of the old DC's might have done this but most had a Y connector with two 4" outlets you could remove. Lots of guys have removed the circular plate on the intake housing of the DC blower (the one with lots of sheet metal screws around it's circumference) and made one with a larger inlet diameter from a piece of board and an HVAC starter fitting/pipe fitting in 5" or 6". Most of the blowers have this removable plate.

[Loren Woirhaye]

I have 2 dust collectors but I run each on its own ducting. I'd rather have one but it would involve a lot of work to consolidate and do the switches and blast gates.