Bosch PRAESENSA - Page 21

PRAESENSA Installation wiring | en 21
Bosch Security Systems B.V.
Underwriters Laboratories Listing Document (ULLD)
2021.12.21 | V0.15b | F.01U.402.882
Cable type recommendations
Mains cable
– Use the supplied mains cable that came with the multifunction power supply or an
equivalent.
– Connect the mains cable of the rack with a fixed connection to the mains branch circuit.
Loudspeaker cable
– When selecting cables and wire gauge take into account the length and loudspeaker load
to avoid excessive power loss. Make sure that the signal level at the end of the
loudspeaker line has not dropped with more than 2dB (this is approximately 20%), as
this will also affect proper operation of the end‑of‑line device.
The table shows the required wire size for copper wires, to keep the loss at the end of
the loudspeaker line below 2dB, when all the load is at the end of the cable. In practice
the load will be more distributed and then the attenuation will be less than 2dB. Round
up the actual load power and cable length to the next number in the table.
Copper clad aluminum (CCA) wires are cheaper but have a higher resistance than copper
for the same diameter. When using CCA cables, take the next bigger wire size from the
table. Examples:
– A 150W loudspeaker load on a loudspeaker line of 480m in a 100V system. Round
up to table values 200W and 500m. This requires 1.5mm
2
copper wires or 2.5mm
2
CCA wires.
– A 150W loudspeaker load on a 1200ft loudspeaker line in a 70V system. Round up
to table values 150W and 1312ft. This requires AWG14 copper wires or AWG12
CCA wires.
– When selecting cables and wire gauge take into account the maximum loudspeaker cable
capacitance specified for the amplifier.
– When end-of-line supervision is used, take into account the maximum loudspeaker cable
capacitance specified for the end‑of‑line device.
Conversion
mm
2
0.5 0.75 1 1.5 2.5 4 6 10 16
AWG 20 18 17 16 14 12 10 8 6
Cable length Minimum wire cross section [mm
2
]
[m] [ft]
1000 3280 0.5 0.75 1.5 4 6 6 10 10 16
900 2952 0.5 0.75 1.5 2.5 4 6 10 10 10
800 2624 0.5 0.75 1.5 2.5 4 6 6 10 10
700 2296 0.5 0.5 1 2.5 4 4 6 6 10
600 1968 0.5 0.5 1 2.5 2.5 4 6 6 10
500 1640 0.5 0.5 0.75 1.5 2.5 4 4 6 6
400 1312 0.5 0.5 0.75 1.5 2.5 2.5 4 4 6
300 984 0.5 0.5 0.5 1 1.5 2.5 2.5 2.5 4
250 820 0.5 0.5 0.5 0.75 1.5 1.5 2.5 2.5 4