Hi all
am I correct to say that a submergible pump will have the pump submerged and the motor (if motor is used) above/outside the liquid, compared to a submersible pump that immerses the pump and motor as one?
We have a large tender specification that requires us to specify VFD's to a series...
We are involved in a project whereby the consultant are specifying the accuuracy of electrical meters used for monitoring onlyas +/-1%. My expereince is that monitoring is typically +/-5% accuracy and actual metering would be +/-1%. This is a building going for 5 star level NABERS (Australian...
"noun 1 the action or process of innovating. 2 a new method, idea, product, etc."
(Oxford English Dictionary)
A recent workshop I was involved in recently brought some interesting responses.
What is your own description of innovation? I'm keen to understand other replies from those who are not...
Is this finally the end of LS&E? http://www.drives.co.uk/fullstory.asp?id=1979
if it is, it is a sad day for not only a British company but a great engineering history going back to 1883: www.laurence-scott.com
I was reading another thread recently and there was a discussion about starting 7000hp motors DOL. I didn't want to tangent the thread by asking more questions about the actual effect of going DOL with such a large motor (it was on a 13.2kV supply) as I was advised by far more knowledgable...
I wonder if somebody could explain, in quite simple terms, (or point me to a decent informative website)how the term 'tonnage' is derived with respect to chiller refrigeration. I found the statement that "A refrigeration ton is the power required to cool 1 short ton of water by 1 °F" but am...
I have posted a question in the "pump engineering" forum relating to the above (thread407-153018). If anyone in this forum also has useful feedback, it would be appreciated.
Thanks
A query came through our USA sales channel asking about the use of a VFD on a Vertical Turbine Pump, 100Hp rated (little else at this stage).
I recalled an application I did with one about 8 years or so ago and one of the main issues with using one with a VFD was:
1) The acceleration time had to...
I'm responsible for writing the product specification for our next generation VFD (variable frequency drive) for the HVAC industry. Part of the process is to obtain new ideas, new requirements from around the world.
Recent feedback from our people in the USA, especially California, is to have a...
This is really aimed at the experts in the US.
Working for a large European drives manufacturer, I can read the various explanations of what constitutes a NEMA 1 and a UL type 1 enclosure (this is around a VFD by the way). However, after numerous discussions with our teams in the US, I still...
I'm looking for some detailed information on the combination of scroll compressors with a VSD (VFD if you're in the US). More specifically I'm trying to find typical efficiency/performance curves that highlight the benefits (if any, but I'm pretty sure there are) of using a VSD on a scroll...
Pump experts
As more and more vsd's/vfd's are controlling pumps, a question keeps cropping up in our (VSD) team " will vsd controlled pumps eventually replace throttle valves?". We make both. Just wondered what real users feel.
Has anybody any practical experience of the flying start function on VSD's (catching a spinning motor) when the motor is not spinning? It's not a trick question, I am finding a number of strange characteristics when the function is activated but the motor is not actually spinning, especially...
A tender specification from a well respected consultant recently passed my desk. Part of the requirements under the Variable Speed Drive specification was: "...the VSD's shall be capable of operation without damage for a period of four hours on a 415V +/-25% three phase power supply and any...
I'm looking for information on what sort of planning guidelines/standards are applicable in Japan with respect to the application of non-linear loads to the electricity network (Harmonic Generating loads). In the same way the USA has IEEE519.2 and the UK electricity generating companies have EA...
