Page 1 of 1

Negative to Ground connection

Posted: Wed Jul 06, 2016 10:11 pm
by jonb42
I'm installing a CCR1009-8G-1S-1S+PC and it seems that the negative of the POE supply as well as the negative of the DC power supply plug are connected to ground (the metal case, ground nut etc). Can someone confirm that this is the case?

I'm using these with Netonix WISP switches that provide POE from 48V DC. Netonix claims that they want negative to be isolated from ground for their 48V power supply. However if the Mikrotik product is connecting them then I may as well bond them together deliberately at the power source.

thanks
Jon

Re: Negative to Ground connection

Posted: Tue Jul 12, 2016 2:25 am
by jonb42
Anyone have any feedback on this?

thanks
Jon

Re: Negative to Ground connection

Posted: Tue Jul 12, 2016 1:40 pm
by janisk
you cannot use -48VDC on that router.

Re: Negative to Ground connection

Posted: Wed Jul 13, 2016 1:05 am
by jonb42
Thanks for the response.

To clarify, I'm not looking to use this with -48V.

Instead I'm wondering whether the negative of the POE supply as well as the negative of the DC power supply plug are connected to ground inside the switch (the metal case, ground nut etc). Perhaps your answer re -48V does address this (because obviously if negative is connected to ground then its a given I can't use -48V!) but I wanted to make sure that is what you are saying to avoid ambiguity.

thanks!
Jon

Re: Negative to Ground connection

Posted: Wed Jul 13, 2016 10:51 pm
by Petzl
the negative is connected with the ground in all mikrotik products.

why power it with POE ?

Re: Negative to Ground connection

Posted: Fri Jul 15, 2016 12:34 pm
by janisk
except for RB800 (from the routers that are currently on routerboard.com)