Use 48V Power Supply on a Phone with 24V

[Anonymous]

Hi!

Just bought some pre-owned IP550 and IP650's (with side panels)

On the phones themselves, it's printed "24V DC" where you plug in the power plug/cord.

Some of the phones we bought, came with a larger power supply, being 48 V DC instead of 24 volts.

I asked the former owner about this, and he just said "yes, some of the phones had bigger power supplies, that's all I know" ...

So, can I assume the phones have no trouble getting double voltage?

It feels wrong when the print says 24V DC ... 🙂

(I don't recall if PoE is 24 or 48 volts ...)

--

Phil

[SteffenBaierUK · Accepted solution]

Hello Phil,

welcome to the Polycom Community and I have moved your post to the right section.

I am unsure about the VSX reference in the Subject but the Phones can only be used with the correct power supply providing the voltage printed on the phone.

A SPIP670 for example would use 48V where a SPIP650 would use 24V

Please ensure to use the correct power supply to prevent damage to the phones.

Please ensure to provide some feedback if this reply has helped you so other users can profit from your experience.

Best Regards

Steffen Baier

Polycom Global Services

[Anonymous]

I don't recognize the current Subject, my original subject was different.

(This subject line was suggested as I typed, as a relevant earlier subject, not sure why it has replaced my original subject)

I only have IP550 and IP650's, they all have printed 24V DC.

But as you can see in the attached image, three of the phones has been used with 48V DC power supplies previously (or so the seller claims) ...

[Anonymous]

Well, actually, one of the phones seems to be an IP560, using 48V ... so I have 10 phones, and two with the wrong PSU, it seems ...

[Anonymous]

It'd be great if we could get a technical explanation here as to why they phone might be damaged with a 48v power supply.  PoE switches supply between 47-52 volts, and a SPIP335 for example can be powered via PoE.  I was hesitant at first too, but have had a 335 at home powered off a 48v power supply, and it's been working great for 3 years.  When I thought about it, it makes sense, given that all of our phones at the office are getting 48v via PoE.

I've seen a few other devices that have a wide range of acceptable voltage, from sound cards (the metric halo 2882 accepting 9-30v dc) to guitar effects and pickups taking 9 to 18volts with no problems.

What I'd like to know is, are there any components in between the DC power jack and the LAN jack that would make it safe to supply ONLY 24V to the DC jack, and ONLY 48V to the LAN jack?

The reason I'd like to know, other than just being technically curious, is business-related also:  If we could order only 1 part number for power supplies going forward, it would save a considerable amount of administrative work, and it would be great for our sales staff.

I opened a ticket already and was given the 'official' answer, but I'd like the official answer to change, if there is no technical reason for the current one aside from fear and apprehension.

Thanks!

[SteffenBaierUK]

Hello aconlon,

welcome back to the Polycom Community.

Could you kindly post the Polycom ticket reference starting with 1- ?

The IP 550/650 phones for example operate from 24V auxiliary DC inputs or 48V (nominal) PoE input voltage.

The input circuitry on the IP 550/650 can tolerate 48V on the auxiliary DC input, but its not recommended.

Also, the pin on the DC jacks of these phones accept a 2.1mm inner diameter plug type, per the 24VDC Power Supply Adapter.

The 48V Power Adapters shipped with other phones mate with a 2.5mm pin on the DC jacks of those phones, so plugging a 48V PSU into the IP 550/650 will fit loose and may not make a connection to the inner pin.

As always, our mantra is: “Use only the power supply adapter that was shipped with the phone on that particular phone”.

Please ensure to provide some feedback if this reply has helped you so other users can profit from your experience.

Best Regards

Steffen Baier

Polycom Global Services