Cloud Electronics PM12 - Manual (Page 14)

PM4/8/12/16 Installation and User Guide v2.2 14
Power Requirements
The PM can be powered either by an external power supply, or from a Cloud host
mixer.
Using an External PSU
An external power supply can be connected to the PM via the 2.1 mm coaxial power
socket on the rear panel. A suitable external PSU is the Cloud CPM-PSU. Other
AC or DC external supplies can be used with the PM provided they are capable of
providing 107 mA at 9-17 V AC or 12-24 V DC.
IMPORTANT: Many DC adapters have poor regulation, and some nominally 24 V
supplies can produce voltages sufficiently high to cause damage to the internal
electronics. If in doubt, use a 12 V AC adapter such as the CPM-PSU.
As the PM incorporates a full-wave rectifier circuit internally, the polarity of the
2.1mm jack is unimportant.
IMPORTANT: The external power supply should not have one side of its output
earthed, as this may introduce earth loops to the system. Most - but not all - plug-
top adapters meet this requirement, but installers should check for earth-to-output
continuity with a test meter if there is any doubt. The integrity of the system’s mains
earth should NEVER be compromised to meet this requirement or to solve any earth
loop problem.
Powering from a Cloud host mixer
If the PM is to be connected to a Cloud host mixer, DC power may be obtained from
the mixer as long as it has a suitable power supply connection, and the spare current
capacity of the mixer is sufficient. As a general rule, a mixer cannot supply power to a
PM that has more zones than itself.
Note that no external PSU should be connected to the microphone. Connecting
an external PSU will override the current draw from the host, and it will power the
microphone instead.
There are two ways in which a PM can be supplied with DC power by a Cloud host
mixer:
1. Via the Digital Paging Interface. The CAN PORT OUT connector on
the PM is wired for power, so a PM connected to a Cloud host mixer fitted
with the Digital Paging Interface can obtain power through this connection.
In systems with multiple, “daisy-chained” PMs, it is only the “last” PM on the
network - i.e. that connected directly to the host - which can be powered in
this way. See “Systems with Multiple PMs” on page 27 for more information.
Note that when using the Digital Paging Interface, the maximum