What rating of fuse will be suitable?
|Rod Renshaw||30/04/2019 22:45:28|
|174 forum posts|
I have an " Align" brand slow motion table drive on my mill, and as this required a 110v input supply and my mains supply is 240v I bought an "Align" step down transformer to go with it. This has worked well for some years, but then it stopped! I have tracked down the problem to a fuse in the transformer box which has blown - probably because I stupidly caused the motor to stall. I am hopeful that this is the only problem and that replacing the fuse will be a solution.
Problem is I can't read the markings on the Chinese fuse. The drive unit is a Model CE-500S, rated at 110v 90W. A simplistic calculation says 90W divided by 110V = just less than 1 Amp. ( The fuse is on the output, 110v side, of the transformer) Is a 1 Amp fuse enough or should I uprate the fuse to allow for startup current etc? Also, should this be a slow-blow fuse? The original fuse seems to have been a simple quick blow type with a transparent glass body and presumably it had a single wire inside it, but there is no trace of the wire now.
Can anyone offer any advice about this?
Thanks in advance.
|john swift 1||01/05/2019 00:19:28|
318 forum posts
yes but , it all will depend on the drive having an interlock that forces you to start at a low speed
if you can start a full speed then a 1A fuse will be too low a current - you may need a 4 or 5A fuse
using a slow blow fuse will help -
for example if the original fuse was a 1A slow blow fuse would be marked T1.0A
Edited By john swift 1 on 01/05/2019 00:19:52
|115 forum posts|
I have three Align units, but only one in operation and readily accessible at this time.
The Align transformer, which has not been put into operation at this time, has a 3 Amp quick blow fuse. This is as supplied and the fuse rating is stamped on the ends of the fuse.
The operating unit is fitted on a RF31 mill drill with a home built step down transformer unit constructed using a toroidal transformer. With this unit I experimented a little with fuses starting with a 1 Amp quick blow and working up. After blowing a couple of 3 Amp slow blow fuses I stepped up to a 5 Amp quick blow and have had no further issues.
I haven't experimented with the motor speed setting at start up so I do not know how this might affect the inrush current. I suspect the load on the motor as determined by the alignment and smoothness of operation of the drive train and weight of the table and any work piece on it would have the most affect on the inrush current on start up.
Hope this helps
|Rod Renshaw||01/05/2019 19:48:15|
|174 forum posts|
Pero and John
Thanks for your guidance on this. I have now fitted a 5 Amp fuse and all is well!
The fuse is a quick blow type which is all I was able to source locally, but I will order a few slow blow as spares.
If anyone else has this type of problem it may save time to be aware that the green indicator lamp on the Align transformer box only shows the presence of the mains input, and gives no information about the state of the internal fuse or the 110 v output.
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