This was asked for in another thread, but I thought it important enough to be placed in its own thread.
There is a filter efficiency Gauge now on the exhaust port of the system. It’s on top of the arm, and can be seen when looking above the filter, while standing to the left of the collector unit. It reads from 0 to 5 Inches WC (convert to PSI by multiplying by 0.036).
http://www.oneida-air.com/Images/Products/Large/filter-efficiency-gauge.jpg
There are two types of filter maintenance:
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Blow down - using the compressed air hose located near the collector, take the blower nozzle, hold it about an inch away from the filter, tilt it at about a 20 degree angle, and vigorously blow air up and down the pleats in the filter from top to bottom, moving around the filter a couple of times. This dislodges the dust that is caked inside the pleats on the inside of the filter.
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Remove the filter, take it outside by the loading docks, put on a respirator and safety glasses, and use a compressed air hose and nozzle, to dislodge the cake inside the filter, by careully blowing them out. Keep the nozzle a couple of inches away from the pleat, and angled down at about 45 degrees (if too straight, you’ll blow dust further into the filter media and ruin the filter). This is a nasty job. It will produce a large dust cloud, your clothes will get filthy, you’ll have dust in every orifice, and probably piss a bunch of people off getting their cars dusty. But it’s there’s just no other way to really get the filter clean, once the cake inside gets to a certain point. Be sure to reconnect the ground clamp to the mesh on the filter itself - not the bracket above it.
When to clean:
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Pressure reads between 3.0WC and 4.0WC - blow down the filter using procedure #1 above.
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Pressure reads greater than 4.0WC - full clean using procedure #2 above.
The gaskets used in the filter are rated to 5WC. When that pressure is exceeded, the gaskets will blow out, and the collector will begin spewing powder fine dust directly into the woodshop. At this point, you should be wearing a respirator at all times while in the woodshop.
A single MDF job cut on the CNC Router, can produce enough powder fine dust, to send the gauge to 5.0. It is imperative, that people cutting MDF ensure their feed and speed is producing chips, and not dust. It is an extremely crappy thing to do, to blow up the filter, and not clean it - leaving the nasty job for some other person to do.
More info:
At 1.0WC exhaust pressure, the system inlet (vacuum) flow is about 1625CFM
At 3.0WC exhaust pressure, the system inlet flow is about 925CFM
At 5.0WC exhaust pressure, the system inlet flow is about 500CFM - not enough to fully evacuate any single tool in the shop.
The lid sensor is an infrared optical unit. It should be wiped off every time the lid is removed from the barrel.