nv relay

Though otherwise in excellent condition my recently acquired Student 1800 has no No Volt relay. All that remains is a black blob that at some point,
after it melted, has been removed from the circuit :-) Any thoughts on a suitable replacement and a source welcome.
thanks
--
Roland Craven
Nr. Exeter, Devon, UK
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Roland Craven wrote:

Roland,
I'm not familiar with the exact device but if appropriate you might be best served by fitting a whole new unit - Machine Mart amongst many others sell them, or if you are electrically savvy, wiring one up based on a conventional relay. If you do go down the latter route, remember that you won't get the thermal overload trip this way. hth
Bob
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
B&Q sell such suitable things in their RCD adapter plugs, thereby giving you earth leakage as well as no-volts protection. About 20 ISTR
There are two types, one is no-volts-release for our type of application and the other is no-volts-hold which is rather essential for your deep freeze should the power go off during your annual hols! Therefore, as they're displayed side-by-side, ensure that you pick up the right type!
I think that they're probably not so good as the main power switch, possibly not having the current handling for repeated switching of inductive loads, but if you've a separate beefy on-off switch, then that'll be OK, because at the point of no-volts-dropout, there's no volts to break as it'd have already been removed by the local electricity board, if you get my drift.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Roland,are you running three or single phase? Are you talking here about a contactor or an overload relay that drops a contactor out in the event of a phase missing or a motor overload. Do you want a complete panel to turn off in the event of low/no volts or do you want to protect a motor?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Hi Mark Three phase and its effectively a contactor that drops the volts if e.g. the chuck guard is opened, the end cover removed, the mains fails, or the brake is operated. Without it I hit the brake and when I release it the motor restarts. Annoying and potentially dangerous. and I won't scrap it even for you ;-) Compared to my old Raglan its a dream - anyone want a Raglan 5"?
thanks Roland
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Search for DOL or direct on line starter on ebay, you should find a wide range of ratings available, just ensure you get one rated correctly for your motor, probably 2.5 to 3A if you have a 2HP motor. Martin
--
martin<dot here>whybrow<at here>ntlworld<dot here>com



Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Is it something which allows/disallows the main motor contactor operation? If so, it's probably only switching the contactor coil current so a basic relay with the right coil volts (AC presumably) and a spare pair of contacts could be wired as a latching relay to do the job. How is it switched on in the first place? I'm not clear as to why an extra relay is needed, I'd have thought the main contactor could be wired to do the same job?
Tim
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I`m not clear about it either Tim. Roland needs to come up with more info.Does the motor on these start with a push button or do they come on when you pull a clutch style lever or twist a switch? Without actually knowing how it`s done or seeing a wiring diagram it`s impossible to say what`s needed.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.