Connecting different phases to LOGO! 230RCE and DM16 230R inputs

Hi, 

there seems to be a mistake in Siemens documentation with regard to multi phase connection for the LOGO! 230RCE inputs. I checked multiple documents and they contradict each other or even themselves regarding this question. 

I understand that you can't mix the phases within the same group of four inputs. But it is not clear what phase can you use for power supply (L1) of the base and expansion modules. 

According to the diagram on page 48 of the Logo Manual (https://support.industry.siemens.com/cs/attachments/109741041/logo_system_manual_en-US_en-US.pdf?download=true) power supply (L1) can be different phases for the base module and expansion module. But according to the caution on the page 41  the phases for L1 of the base and expansion module must be the same! 

According to this document (https://assets.new.siemens.com/siemens/assets/public.1542881817.f583a4ec-cfaa-4e6f-a931-0cbcb5d3652a.go182-en-gewusstwie.pdf )  the power supply (L1) can be different for the base and expansion module BUT the power supply must come from the first group of inputs on the module!

But according to page 8 of this  document (https://support.industry.siemens.com/cs/attachments/109755865/109755865_LOGO8_TDE-CentralControl-RollerBlinds_en.pdf) the power supply (L1) must be the same for all modules and doesn't have to come from the first group of inputs.  

All the documents can't be right because they directly contradict. 

Logos are part of my house automation project. I am using LOGO! 230RCE basic module with two DM16 230R expansion modules. All the inputs on the basic module and the first expansion module will be connected to phase L1. But the groups on the second expansion module will be connected to different phases (group 1 to L2 and group 2 to L3). What phase do I connect to the power supply of the second expansion module? 

With only electrical view it may be possible to use the phases as you want, also inside the groups, it will work. But there are rules for minimum electrical spacing between terminals and conductors on the circuit boards. Don't ask me for the specific rules, but when you show the terminal layout, you see the quad terminals of the groups with additional space.

In the last manual of the Logo8.2 i read out following rules:

1. On base modules and DM16 extension modules the phase of the power supply must be the same as for I1 to I4, any other phase can be used for I5 to I8

2. On DM8 extension modules any phase can be used and must be the same for supply and I1 to I4

If you need alle three phases, you at least need one DM8 extension module. For a logical sequence i would prefer L1 for supply of base and I1 to I4, L2 for I5 to I8 and L3 for supply of extension and I1 to I4.

Regards, Scorp

LOGO! Support

Therefore you can use L1 for the power supply, L2 for I1..I4 and L3 for I5..I8.

In all examples of the manual you can see, that the power supply has the same phase as I1 to I4. Maybe that is only why it makes no sense to have a phase without inputs ?

In the system manual 03/2019 is following information in chapter 2.3.1 page 41.

Expansion modules DM8 230R and DM16 230R must be operated with the same type of
power supply (DC or AC) as for the connected 230 V version of the LOGO! Base Module.
The same supply output "+/- "on DC power supplies or "N/L" on AC power supplies must
connect to the same phase on both the expansion module DM8/16 230R and the
connected LOGO! 230 .... Failure to follow the instructions could result in personal injury.

Does it mean, i have to use the same phase for supply power of base and extension ? Then there is a fault in the wiring examples on page 48. I understand the uncertainness of the users and most of them are not able to study all rules.

Regards, Scorp

 to both for answering so fast. 

Then if I understand correctly I am safe if I connect all the power supplies (for base and both extensions) to phase L1 and groups of four inputs to any phase , right?

I would connect it in your form to avoid problems with rules. I think, it is the best way to supply all Logo modules with the same phase behind one circuit breaker and i also would try to use one phase for the inputs if possible. In most cases you only need some interface relays.

Far better is the usage of low voltage (e.g. DC24V) for supply and inputs in new projects. But this is dependent on the possibilities of the wiring, because you have different voltages for control and load.

Regard, Scorp