------Question for meanwell 1500V input dc/dc converter and WJ30-4_WJ30-H Please Put your question below------
We need 600W of power, so we would like to operate two such units in parallel? How would I do that?
Secondly, we are planning to switch the converter on to a live 1500V source by direct connection without precharging. Will the accessory fuse specified work if used in this manner.
Hello,
I am currently checking with Mean Well on this to confirm if these can run in parallel.
Datasheet for the product can be found here.
It would appear to be a fuse & DIN mountable holder assembly, having a 4-amp rating at the low end. From a 1500V bus that’d give a 6kW carrying capacity (more than 10x the indicated need) so the interest in parallel operation is unclear.
Details are extremely relevant to such a question, and a 1.5kV source is not the sort of thing one should take lightly.
The part in question is NOT suitable for use as a connect/disconnect mechanism under load.
If the thrust of the question is more along the lines of whether or not the fuse will tolerate the load associated with the plugging event (actual switching being done by something else) it would be necessary to evaluate the inrush characteristics of the load against the I2t characteristics of the fuse element.
Also, the item in question should not be used with any source capable of delivering short-circuit currents in excess of its indicated 10kA breaking capacity.
Rick,
This fuse is recommended for use with this product. The inrush current for the power supply is stated on the data sheet. I have 1500VDC available and I need to provide a little under 500W at 24 VDC. That’s why I want to operate two RSDH-300-24 DC-DC converters in parallel. The data sheet says that the “Cold Start” inrush is 500A @1500VDC. Now a 4A fuse is recommended for use with a single power supply. My research says that the fuse is likely to blow with such a big inrush current. If I knew the front end capacitance, then I might be able to estimate the inrush and provide a suitable countermeasure. So I offer the following diagram showing how I plan to startup and operatethis power supply:
So my questions are:
image002.emz (6.64 KB)
oledata.mso (27.6 KB)
I didn’t see a converter part number in the initial post, hence my confusion. This makes much more sense.
The blunt-force way to do this is to buy one, pull the screws, and look. We’ll see what Rob’s inquiry returns, but my experience suggests that cracking a seal and looking for oneself can be a very good way to get important information.
Regarding paralleling of outputs, the datasheet indicates presence of a current limiting protection mechanism.
In conjunction with the V-I characteristics of an external OR-ing diode, the parasitics of the interconnect conductor(s) and/or any deliberately added ballast resistance, it should be possible to make multiple units play nicely together. Some supplies are made to work as a team, others can be made to work as a team. Where there’s a will, there’s a way.
Regarding input fusing, suggestions of the sort found in the datasheet for the supply in question aren’t written in stone and may come with unwritten caveats. I’d be wary of subjecting a 4A rated fuse to repeated 500A surges if nuisance tripping is to be avoided.
I’m having trouble accessing the information offered. The email response feature frequently results in such disconnects, as well as unintentional exposure of personal information contained in email signatures. Interaction via the forum site for followup dialogue limits these adverse effects.
Rick,
I looked at the situation with that fuse and the inrush and decided that the best remedy is to put an NTC inrush limiting thermistor in the input. That is cheap, and the most expensive part of it is the engineering and tech labor to mount it.
