FBT 37483_VAIE2550_manual1.pdf - Manuale (Pagina 71)

5-2
CONNECTIONS AND SIZING
UK
5.1.2 100V 490W system - 1 off VAIE 2250 with FBT dedicated external amplifier (cod. MPA 5240)
Sizing - Check of the loading power of the loudspeaker lines
Measure the impedance of each speaker line with an 1 kHz impedance-measuring device:
- Impedance of Line L1A, zone 1: ZL1A (
Ω)
- Impedance of Line L1B, zone 1: ZL1B ( Ω)
- Impedance of Line L2A, zone 2: ZL2A ( Ω)
- ....
- Impedance of Line L6B, zone 6: ZL6B (
Ω).
Calculate the power load absorbed by each line with a 100 V amplifier output:
- Loading power of Line L1A, zone 1: PL1A = 10000/ZL1A (W)
- Loading power of Line L1B, zone 1: PL1B = 10000/ZL1B (W)
- Loading power of Line L2A, zone 2: PL2A = 10000/ZL2A (W) etc.
The sum of the power absorbed by the lines connected to zones from Z1 to Z3 must be lower than 250W:
P.tot. Z1÷Z3: PL1A + PL1B + PL2A + PL2B + PL3A + PL3B = < 250W
The sum of the power absorbed by the lines connected to zones Z4 to Z6 must be lower than 240W:
P.tot. Z4÷Z6: PL4A + PL4B + PL5A + PL5B + PL6A + PL6B = < 240W
Note:If it is planned to use the system to broadcast background music with a greatly attenuated volume for some zone outputs (zone
volume -15 dB or -9 dB), it is advisable to connect a speaker load of at least 20 W to these zones, in order to improve stability of the
diagnostics of the speaker lines.
Example: PL1A + PL1B = PZ1 > 20W
Setting the system operating mode: “WITH EXT. AMPLIFIER”
For details about programming this operating mode, refer to the “set > AMPLIFIER MODE” menu (see point 8.7.5).
Install only speaker units with 100 V
constant voltage line-repeating coil