Rewiring/replacing a roto control board

Hash and Stuff Extraction
, ,
1

Hey everyone!

It’s been a while since I’ve posted but I have a question for the group. I’ve recently started looking into medium scale ways to decarb crude under vacuum. I’m tired of babysitting hot plates and I need more throughput anyway. One obvious solution is to decarb in a large rotovap. My problem is that my roto (AI 10l) only goes to 99c. I’ve heard tell of industrious lab rats either rewiring or replacing the control board in order to get their units to go hotter. Does anyone have any experience with this procedure that they would like to share?

Not being a noob I tried the search bar first. I didn’t see anything on this topic, but rotos are a popular subject and there were a lot of results. I may have missed it. If this has already been discussed could someone share a link?

Thanks everyone!

2

@cyclopath, is this a trick you’ve performed? I feel like @SidViscous may have also done some similar rewiring and tinkering (maybe not on a roto).

1 Like
3

I recommend just disconnecting the heating element in the bath from the existing controls and wiring it up to an appropriate SSR/contactor. Then add a PID with a relay output (available for like $30 off Amazon or wherever).

You can check the element resistance with an ohm meter to calculate the draw (V=IR). Adding a fuse or breaker is also not a bad idea.

Bonus points if you can use the same temp sensor (usually a 3 wire RTD but it differs between units). Honestly it’s not a big deal to just tape one to the outside of the bath.

If you need more in depth details I can happily help, not sure how much electrical experience you have

7 Likes
4

Hahaha you guessed right, I was typing at the same time lol. Right now I’m fighting with a cheap replacement stepper motor because a unit we got off Craigslist had a weird ass 300VDC motor that gave up the ghost. With how many of these things I end up kludging together I’m going to consider ripping all the controls out and putting them on a single PLC/HMI.

3 Likes
5

Where are you located? If anywhere near Colorado I can help you select and wire in a pid and ssr. Depending on unit might be able to reuse the ssr and just install a new pid unit

3 Likes
6

Enough experience to be dangerous. :slight_smile:

Thanks for the outline! I was hoping to just use the existing equipment and controls just for the elegance of it, but I’m not opposed to a custom build either.

3 Likes
7

I’m in Central Massachusetts, unfortunately. Let me know if you’re ever in the area and we can sesh though!

4 Likes
8

UL listings are just a pyramid scheme anyway!

2 Likes
9

There have definitely been people talking about “unlocking” the PID settings on here but I have no idea how it’s done. Maybe @EffisonAndy could help you out, he’s pretty knowledgeable about the controls on these units. It would probably help to know the exact unit you’re planning on “fixing”

1 Like
10

Just a regular Across 10l unit. I think they list is as SE26, but I think that’s just an item number on their end.

1 Like
11

I see this but I’m guessing you also found it already and it didn’t help:

3 Likes
12

I did not see this! Thank you!

2 Likes
13

Ayyyyy!!! I’m in the Greater Boston area, we should totally sesh some time!!!

2 Likes
14

If you call them they will tell you,you push in the dial to bring up the menu its been many urs since i dis it so dont want to tell you the wrong sequence. Just tell across tour not an idiot and you know that you cant run it that hot with water and they’ll tell tou

2 Likes