1 VMB8PB per floor connecting up to 8 separate push buttons

lvmax · September 10, 2009, 11:22am

Hello,

Could you tell me if I can put 1 VMB8PB module per floor to control 8 separate push-buttons, in a house (or do I have to put 1 VMB8PB per push buttons) ?
Any recommendation regarding the cable to use ?

House is about 9 meters wide per 10 meters long.

Thanks.

VEL417 · September 10, 2009, 11:50am

The maximum cable length between your pushbuttons and a VMB8PB is 20cm, so your option will not work.

sven · September 10, 2009, 4:12pm

So that means that after each pushbutton you must have a VMB8PB?

Is you have a VMB8PB module and you have 10m UTP to a push button it doesnt work than?

GertSt · September 10, 2009, 6:20pm

May be it’s not officially guaranteed to work … but I’m using a 5m long UTP cable going from the VMB8PB to 4 buttons without any problems so far … (in use for 8 months now)

VEL417 · September 11, 2009, 6:36am

The VMB8PB inputs are unbuffered. Spikes, radiation or any other interference can cause undesired behaviour or even destruction of some or all inputs of the unit or other parts of the Velbus system, as there is no isolation between the VMB8PB and the rest of the system.
VMB6IN has been developed to be used with long wires.

lvmax · September 15, 2009, 11:09am

If we use the VMB6IN, what is the cable characteristics recommended to be used for the push buttons ?
Can we use one “UTP 8 x 0.51mm” (of course not the same one used to connect other VMBxx modules) to connect let say 4 separate push-buttons using that same cable ?
Thanks.

VEL417 · September 15, 2009, 1:13pm

Not really important. UTP is fine.
Please note that if you do not use the VMB8PB, you do not have the possibility to put feedback leds for every pushbutton.

bert_g · October 15, 2009, 9:03pm

I have a 10 wired cable from all the push button in my house to my main elektrical “cabinet”. There i have connected the cables with the VMB8PB and everything works fine for me!!!

VEL417 · October 16, 2009, 6:41am

Probably it works for now, but it is bad practice. It will cause problems one day, however impossible to tell when.
We do NOT recommend to use the unit this way. Damage to any of the modules on the bus will not be covered by warranty if used this way.

pevo · October 21, 2009, 10:16pm

bey me, there is also 15 metres between VMB8PD and push-buttons And it’s work for a year without problems.
But there is nothing in the user manual thant The VMB8PD behind the push-buttons must.
What might happen? It may cause fire?

VEL417 · October 22, 2009, 6:54am

Of course, it will not catch fire
It will simply stop working or work erratically.