Recent content by richerdick

I worked on an instalation today thet had 3 415 v 16A sockets parelleled up all protected by one breaker. is this common practise? are there any safety implications? i cant see any provided that the cable sizing is adequate for the breaker

i have been asked what are the safety reasons why most three phase isolators dont break the neutral. My response was that the neutral is held to earth potential and therefore is used in testing for isolation also keeping it connected prevents the neutral from floating to a higher voltage . Are...

Sorry it is not a semiconductor fuse just a hrc

Hi it is a semi conductor fuse. Do you think that I can rule out any reference, feedback issues, from causing the fault with the veiw that the field fuses have blown. Although the drive is throwing out clutches my thoughts were that if the field were for some reason weakening that the motor may...

here is what i know about the field. dc voltage 280v set to control to 5250mA and when running normally seems to do this +-20ma. the field is controlled by a conrolled rectifier, two phases with diodes on one half of the bridge and thyristors on the other half. the fuses are 20A and on the ac...

hi yes encoder feedback but would that blow the field fuses?

A dc motor at work is driving a lineshaft that drives 4 seperate levels of machinery via mechanical clutches. we have a problem at work whereby it is throwing out the clutches whilst accelerating. This is happening on a motor drive combination that has been in and running for several years so it...

Does anyone know if I should be able to interface directly with a AB panelview 550 via a 1747 pic when the panel view is not connected to anything else other than a 240v power supply . I have bought one to have a play about with and am having trouble connecting to it?

I was trying to keep cost down, I can get a small smart relay type plc for say £100, i would need to change the limit switches to add contacts and there are quite a few so the cost would be far greater. I am more woried about whether there are regulations that prevent me from interfacing a PLC...

I wish to improve the indication for which guards are open on a machine at work. The current system includes several guards in series driving a dual loop safety relay, the safety relay then goes on to drive an ouput to a plc that indicates that there is a guard open within a specific zone of...

thanks

Hi, I want to run a long cable (>20m) to a 4 wire pt100 do i need to use a special sort of cable? accuracy +-1degree celcius is ok. thanks richard

Comma after punctuation please.

At the time of installation the machine would have met the required safety standard. what i am trying to say is that as current standards have developed they required more advanced safety features for example in this situation the existing guard safety circuit utilises just limit switches...

i am working in a printing press the uk and have been requested to make some modifications to a guarding circuit on the printing press. I have some conecrns with how i stand legally i am sure that some of you will have come across this problem before. the machine has evolved over many years and...