To SSR or not to SSR

Snippy

Building a new coreXY printter using the Duet 6HC.

Im having a dilemma, ill be running two meanwell rsp 500 24, the first one will power the duet and the second one will power a 24v 410x410 heated bed.

Heated bed is 340-360w.
https://www.aliexpress.com/item/1005003056403054.html?spm=a2g0o.order_list.order_list_main.50.613118026jZegx
Measures 1,8ohms

The cheap 80A SSR
https://www.aliexpress.com/item/10000011656519.html?spm=a2g0o.order_list.order_list_main.33.613118026jZegx

Do is run the Out_0 power in from the PSU that runs the duet or the one powering the bed, when using an SSR? What about when not using an SSR?

jay_s_uk

@Snippy 360w at 24v works out at 15A. here's a note from the docs

1 Note that the board is rated to 18A on the '15A high current output'; however it is supplied with a 15A fuse fitted (18A are difficult to source). If you need 18A on the this output then you need to fit a 20A fuse and take further precautions against over-current.

so you'd need to change the fuse to a higher rating, then you should be ok

Snippy

@jay_s_uk
Are they mini or micro2 fuses?

jay_s_uk

@Snippy mini

Snippy

''and take further precautions against over-current.'' any ideas on this?

T3P3Tony

@Snippy a thermal fuse and a current limiting supply for example. Given that I would use the SSR...

Snippy

This post is deleted!

Dad003

@Snippy Be very careful with the cheap chinese SSR , quality is really random .

i use these here for my heat bed and hotend

https://www.auberins.com/index.php?main_page=product_info&cPath=2_30&products_id=674

dc42

@Snippy personally I would use an AC mains bed heater controlled by a DC-AC SSR for a bed heater of that size. If you want to use a 24V heater then the 6HC can drive a 24V 360W heater directly (just) using the standard 15A fuse.

Avoid cheap DC-DC SSRs, they are usually fakes.

hackinistrator

for low voltage high current dc powered bed you can also use external high power mosfet with a heatsink . usually will be cheaper then ssr .