Heated bed 2500 Watt + Duet3 6hc

dutti

@Phaedrux RSU has 27a and the SSR40a. Is this a problem?'
Or must be the current of the SSR less than the RSU..?
thanks

Phaedrux

The SSR rating is just for it's max capacity, not what it draws or anything like that.

What are the specs of your heater?

dutti

@Phaedrux 85x85cm silicon heater
2500watt

Phaedrux

What is your regional ac voltage? 110 or 220?

110 would be ~22a current
220 would be ~11a

theruttmeister

@barbarossa-cologne

I think you mean PSU,

The PSU has a rating for the amount of power it can supply. The SSR is just a switch, but its rating is like a wire, how much current it can carry.

The PSU and SSR are doing separate things, they just happen to use the same measurements (Amps).

Your bed heater will draw ~11 amps (I'm assuming you are in Europe based on your username) with the 220V from the wall, the SSR can carry a lot more (which is good, because the rating on SSR's is often over optimistic) (@Phaedrux I think got those numbers reversed).

The PSU can supply 27 amps, but that is at the 24 volts its putting out, its not being used to power the heater.

One thing to keep in mind, if you do something crazy, like max out the PSU by using it to drive an extra heater or a heated chamber... The combined power requirement would be over 3000 watts.
That would be more than is safe on a normal European wall plug (they are normally 13A max).

dutti

@theruttmeister
yes, of course PSU. sry
Rigth. I´m in cologne. So it´s 220v.
So when I understand it rigth, I should buy a second power supply with more volts for connecting the SSR and the heater?

thanks for the explanation

Phaedrux

@theruttmeister said in Heated bed 2500 Watt + Duet3 6hc:

@Phaedrux I think got those numbers reversed).

Yup I did, sorry.

dc42

@barbarossa-cologne said in Heated bed 2500 Watt + Duet3 6hc:

@theruttmeister
yes, of course PSU. sry
Rigth. I´m in cologne. So it´s 220v.
So when I understand it rigth, I should buy a second power supply with more volts for connecting the SSR and the heater?

Is it a 220V AC bed heater? If it is, then you don't need a PSU for it. If it isn't, then you have the wrong SSR and we need to know what voltage it is.

Tom Sanladerer posted a video on using SSRs to control AC mains bed heaters here https://www.youtube.com/watch?v=TiEwNf1H_Tc.

dutti

This post is deleted!

dutti

correct?

theruttmeister

@barbarossa-cologne

An SSR is just a switch. The control side only needs to be 24V (actually anything from 3-48V is common, the SSR will be marked), the PSU is powering just the switching of the SSR, which uses a very small amount of power.
The whole point of using an SSR is that the other side of the switch can be for much higher voltages and can carry lots of current.

So your wall socket can supply up to 13A, your SSR can carry 25A and the bed only draws 11A. Everything is good.

The PSU is not powering the bed in any way at all. Its just controlling the switch.

dutti

@dc42
It's a 220v heater.
Thanks for the video link.
I think @theruttmeister
thanks a lot
It's working but heating up needs a lot of time. How can I change this?
23 to 60 degree needs 10 or more minutes
Thanks

theruttmeister

@barbarossa-cologne

If you haven't already, insulate the back of the heater. That can make a huge difference.

All the other options are lots more difficult: More powerful heater (needs a non-standard wall socket, unless you have a 16A or 32A Ceeform?), smaller bed (that 85x85cm is huge). Thinner bed... which given the size might well warp.

Best bet is insulation, if you don't have any right now, half the heater output is heating the air.

jens55

Do you have the means to measure voltage and current ?
The time required for heatup doesn't make sense if everything is hooked up correctly.

Phaedrux

@barbarossa-cologne said in Heated bed 2500 Watt + Duet3 6hc:

It's working but heating up needs a lot of time. How can I change this?
23 to 60 degree needs 10 or more minutes

Have you PID tuned the heaters and saved the results?
https://duet3d.dozuki.com/Wiki/Tuning_the_heater_temperature_control

dutti

@Phaedrux
I started 3D print 3 months ago. So I´m sorry when I don´t understand some code etc.
Is this picture helpful?
thanks for all

I have to say that this morning it was heating up a bit faster. I disconnected other things from the socket. But it is still slow.... SSR isn´t warm.
the house is about 70 years old... maybe it is not enough power on the socket??

jens55

Ahhhhh .... the guilty party is the PWM setting. You have set the heat pad to effectively be 250W!
Calibration voltage 0.0V ???

dutti

@jens55
Ok. Do you mean 2500 watt?
How can I change this parameters ?

jens55

Remove the portion of your M307 command in config.g that says "S0.1"
Run heater tuning again.
The way you have things configured at the moment is that your heat pad is effectively 250W!

dutti

@jens55
ok I understand.... with S1 or S0.5 its heating much fast,but it comes to a fault. ``temperatur rising much slowly than expected. 1.3.C /sec. (with S0.5 its 0.7c/ sec.)