PMP Synchronization Solutions User Guide
CMM Planning
PMP-0297 007v001 (January, 2017)
3-17
The 30 VDC CMM4 power supply is labeled as 30 VDC and typically measures 30 VDC at its
output. The associated CMM4 terminal blocks are marked 29 VDC, and some associated SM
power supplies are labeled 29.5 VDC.
All of these components are elements of a nominal 30 VDC
system, and can be considered “30 VDC” elements.
The 54 VDC CMM4 power supply is labeled as 54 VDC and typically measures 54 VDC at its
output. The associated CMM4 terminal blocks are marked 56 VDC, and associated SM power
supplies are labeled 56 VDC.
All of these components are elements of a nominal 56 VDC system,
and can be considered “56 VDC” elements.
One of the CMM 56 VDC blocks has 2 terminals while the other has 3. The third terminal provides
an additional grounding point, if needed.
If you are using a CMM4 to power both 30 VDC and 56 VDC systems, then you must install both 30
VDC and 54 VDC power supplies along with the CMM4. These power supplies must be wired to
the correct terminal blocks (marked 29 VDC and 56 VDC).
IMPORTANT!
This advisory only affects operators using a CMM4 that supplies power to
both 30V devices (PMP100 radios) and 56V devices (PMP430 or PMP320
radios) via discontinued ACPS120WA power supplies. This configuration
does NOT require a 1k 5W resistor on the CMM4 29V terminals (This 30V
power supply was made available for order around December 3, 2010).
The phased out 30V model ACPS112WA power supply will always require
a 1k 5W resistor when a 56V supply is present. Since both power supplies
look identical, see the label under the power supply to identify the model.
Power supply model ACPS112WA requires a 1k 5W resistor across the
30V DC input terminal of the CMM4 when both 30V AND 56V are present.
Doing so will prevent the 30V power supply to not always come out of
sleep mode with a light load. The power supply will attempt to come out
of sleep mode, and if it does not see sufficient load it goes into a
sleep/recovery cycle that is observable by watching the 30V LED on the
port connector turn on and off.
Power supply Model ACPS120WA satisfies the European Union's Energy
Level 5 requirement and DOES NOT require a 1k 5W resistor.
See
Procedure 7 Installing a special resistor for dual-powered CMM4s
more information.
The 30 VDC and 54 VDC power supplies are rated for outdoor temperatures, but are not weather
tight and so must be mounted in a communications hut or enclosure provided by the operator.
They should not be mounted inside the CMM4 enclosure, as it is not designed to handle the
additional heat load of the power supplies. (Although it appears there is space for the power
supplies, the key constraint is the surface area of the enclosure for dissipating heat, not the
volume of the enclosure.)
With most of the 30 VDC radios, the radio uses up to 10 W and the input voltage as measured at
the "29 VDC" terminals on the CMM4 must be between 22 and 32 VDC to support 8 APs at the
maximum 100 m (328 ft) Ethernet cable length.
