Power to Network

I have a network that at present has three powered relays (600ma) plus three power supplies (1050ma) giving a total of 1650ma. I need to add two relays which means only one can be powered. This is sufficient power wise at the moment but will leave me at 1850ma so there is no other way to increase power if it is ever needed. The alternative is to add another 5500PS to take me to exactly 2000ma (which seems more sensible) but more expensive of course.

Apart from relays (@200ma), dimmers (@200ma) and the dedicated 5500PS (@350ma) are there any other units that can contribute power to the network?

 

I believe you would be safe to run your network with 2050mA of current.. 50mA isn't going to hurt i wouldn't think..

But before getting too excited and ordering your new relays with powersupplies i would go and calculate roughly how much current your proposed/existing network will draw as your 1650mA may indeed be more than enough..

Remember a maximum of 100 units to a cbus network..

Example huge network..
85 x 18mA = 1530mA (Switches, Sensors, Bus Couplers, Non Powered Relays, etc)
5 x 22mA = 110mA (DLT's)
3 x 40mA = 120mA (Thermostats)
2 x 65mA = 130mA (B&W MK2 Touch Screen)

Total for 95 units requiring power = 1890mA

Obviously the above is just an example but very rarely would a single network every get this large.. Although I have been to a home with 165 units over 3 networks..

I woiuld calculate your proposed/existing network, and then see if you can get away with using all output units with powersupplies and if you still require more juice add a seperate 5500PS..

Cheers,
Nik

 

The original cream box C-Bus power supplies, which have been obsolete for years, could provide 320mA of power. The other unit that provides power to a C-Bus network is the purple Professional series dimmers, which provide 60mA.

 

The old cbus marpa audio switcher supply power too

 

Thanks for all the feedback.

I think 1850mA is enough. I am at 484 ohms (including burden) on the impedance calculation in this network, with 80 units and consumption of 1516mA so there's almost no 'room' left impedance wise to add more (even though there is current).

My understanding from other threads is that this needs to be between 400 ohms and 1500 ohms including burden.

 

If you are at 484 ohms including the burden you can safely turn the burden off or remove it. Removing the burden would give you an impedance of approximately 938 ohms which is safely between the limits of 400 and 1500 ohms.