I have a number of questions regarding using the 7970 IP Phone with PoE. Firstly, I have an IEEE 802.3af power injector that isn't a Cisco brand. It is 48v and I'm wondering if I can use that with the phone, though I understand this is probably not the most recommended resolution because it isn't a Cisco product. I'm just wondering if it has the right specifications to meet the need of the phone (being the 802.3af IEEE 48v interface).
Secondly, I've read that for full screen brightness it is recommended that you get a PWR-CUBE adapter for the phone. What I'd like to know is what the difference is exactly? Is it possible to run the phone, fully featured, without having to get a PWR-CUBE for each of the 7970's we have here. If the screen is just a little bit dark I think we can live with that.
Thanks a lot for all the great assistance you guys have given me. This tool really is indispensable.
Ok, that made me laugh.
Nah, the POE will not burn out the phone at all. It will either power up the phone, or no power will be available for it.
Customer of mine had 4006 CAT switches with POE blades in, but not using the POE function. (no power shelf) So, we got new 4506 switches, pulled the blades out and put them into the new switches, worked like champ. But later, realized that the POE used in the older blades is not the same as the new blades. We could supply power to our AP's in the office, which was odd. Check on some tech specs and turns out, there IS a differene in the newer and older blades. I dont have it in front of me, but that was the issue.
So no, it would burn out a phone, never. It's still standard POE, but the newer version supplies just a tad more into the line.
I'm more of a Reno 911 junkie. So Lt. Dangle is the man. haha
You are most correct using the 48v model. I also found a note indicating 3rd party IEEE 802.3af switches are supported with the 7970;
IEEE 802.3af, also known as PoE, defines a way to build Ethernet power-sourcing equipment and powered terminals. The specification involves delivering **48V of AC power over unshielded twisted-pair wiring. It works with existing Ethernet cable plan, including Category 3, 5, 5e, or 6; horizontal and patch cables; patch panels; outlets; and connecting hardware, without requiring modification. The IEEE 802.3af standard specifies support for two power levels, low-power powered devices at 7W per port and
high-power powered devices at 15W per port.
7970 Power Consumption and Display Brightness for Power Configurations
IEEE 802.3af Class 3 power from a third-party switch
Max. Power Consumed from a Switch 6.3 W
Phone Screen Brightness Approx. 1/2
Hope this helps!