Hello Christian,
The ABB is a top-end VFD.The link you provided goes to a British supplier site. Since you are apparently in Mass, I am a little confused. However, the equipment is pretty much the same either way.
Enclosure: you say it is NEMA 1 rated. The basic drive comes in a plastic IP20 enclosure. The IP20 is suitable for clean environments where physical damage to the drive is unlikely. ABB really thinks you are going to put this in a control panel. It appears that they also offer a NEMA 1 kit to bring the IP20 enclosure up to NEMA 1 specifications. I take it that you have the ABB NEMA 1 kit?
NEMA 1 rating means the enclosure protects people from contacting high voltage parts. It also provides some protection against falling debris, but it is not dust tight or water tight. NEMA 1 enclosures can have ventilation openings as long as it is not possible to stick your fingers or a screw driver through the vent and contact a high voltage part. The vents are often louvers - sometimes screens.
Anyways, a VFD puts off some heat when it is running. A 3 HP VFD puts off about the heat of a 100 watt light bulb when the drive is working hard. The drive has one or more internal fans to cool itself. Ventilation of the enclosure is important so as not to overheat the drive. Unless this is a really large drill press, I suspect you will seldom load the drive to its rated 3 HP, but you still need to allow for cooling of the drive. Over the years I have worked with many ABB and similar drives in industrial control panels. Often there were 8 - 10 drives in a single large panel. These panels were always fitted with one or more "pancake" blowers to pull fresh, cool air into the panel and to exhaust the warm air. The blowers ran in exhaust mode and were located near the top of the panel. The air inlets were near the bottom of the panel and always had a dust filter installed. These filters looked like what you would find in a residential kitchen exhaust fan - made of several layers of expanded aluminum, and were washable. As long as the filters were in place, the inside of the panels remained clean. So, your idea of using a screen or mesh might be workable, but be sure not to restrict the airflow of the cooling blowers.
Braking
Many VFDs have the capability of braking by forcing the motor into a generating mode and using a braking resistor to dissipate the generated current. I don't think you need this for a drill press. If it were me, I would configure the VFD to run in the "coast to a stop" mode, and not even use the "decelerate" feature. That way the drill press stops in a way similar to turning off the switch. FWIW, braking is used in hoists, elevators and other applications where the motor has to hold back a load. It is also used for E-Stops of large rotating machines.
Symbols
For the input power, single phase 240 volt goes into U1 (L) and V1 (N). They ought to just call them L1 and L2 since there is no "neutral" used in 240 VAC.
U2, V2, and W2 are the terminals going to the 3 phase motor. It is best to have the wiring from the drive terminals go directly to the motor connections without passing through a switch of any kind. Opening the 3 phase circuit when the drive is loaded might smoke the drive. Keep the 3 phase wiring as short as feasible (like 6 ft or 10 ft). The high frequency switching on the 3 phase circuit can cause problematic standing waves when the length gets beyond 50 ft or so.
I recommend a manual "safety disconnect switch" on the inlet power, located near the drive. The disconnect provides a means of removing power from the VFD for servicing, or for when you are not using the drill press.
Set Up Parameters
You will have to go through a "set up" procedure before you operate the drive. Don't be scared off by the dozens of parameters that appear to require setting. Many can remain in their "factory default" setting. Probably only 15 or 20 need to be reset.
Some of the parameters to be set include the rated amps of the motor, motor rated speed, rated HP, accel time, decel time, reversing or not, etc.
Read through the set up portion of the manual and try stepping through the menus once the drive is powered up. Then, post again if you have questions on any of the parameters.
Terry S.
