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As for the hardware, there is absolutely nothing to worry about with the MultiPoint. It is truly an impressive instrument. Well, to be honest, the acquisition hardware is exactly that of the Power Recorder. All that has happened is they have built it into a slightly flimsier case (1.2mm steel) and have incorporated CTs into its base. On the reliability front, it is even higher that that of the Power Recorder mainly because it does not get moved around, but also because the hardware is ventilated and does not reach quite the same operating temperatures as its portable brother. I do have a couple of bones (albeit, very tiny ones!) to pick with RPM in that they have never got working two features I would have loved to have seen on many installations of this device. First is the I/O port they have placed on the side (nope, it's not functional) and, secondly, it would would have been great if the RS232 port on the side spewed out the latest readings say once every 5 seconds. But these are the only negatives. The one thing I would warn against with regards the MultiPoint is this is an engineer's instrument (and by engineer, I mean someone who is extremely competent in power quality engineering!). It is not one of those "nice to have boxes" that will only come into action when something has gone wrong. It is a serious tool and, as such, needs to be used by the serious individual only! The voltage inputs are exactly the same as the Power Recorder being 2MW and can measure to 707VACrms. The acquisition hardware (model 1948) is also, as is its 1656 brother, capable of 0.5µs transient capture. This speed (or better) is absolutely vital when putting PQ recorders into data centres. In fact, a facilities manager cannot call himself that if such hi-speed recorders are not employed in his data centre! The built-in CTs are fixed at 5A full scale deflection, but there is a mod (part number 1965) to have normal CT plugs on the side allowing any of the normal range of clamp-on CTs to be employed. Oh, and contrary to belief, this instrument is quite happy to operate on 110V or 220V DC making it superb for sub-station use. Special 48V DC versions are available for the telecoms market. The reason I would be very sad to see this device disappear off the market (and here's truly hoping this report will help alleviate this) is that this is about the only power quality recorder I have seen that allows the complicated hardware to be removed from a base without disturbing the loadings or connections of the supply being monitored. This is extremely important if connected to high classed VTs and CTs.
© 12.07.03 |
MEASUREMENT TECHNIQUES:
Right from the start, I need to say that the only reason I have put "questionable issues" next to this fantastic fixed version of its brother, the Power Recorder, is that there are whispers they are going to stop production of this unit (although, at the end of 2003, there were still marketing drives - so maybe it will still be around for a while).