Loop Design
The loop installed in the lift car needs to be designed and fitted correctly if the
system is to be effective.
Most lifts are built with metal walls and ceilings. Because of the shielding effect of
the metal ‘box’ in such lifts, the loop cable needs to be on the INSIDE of the car.
This is normally achieved by constructing a special loop from metal bars fixed to,
but insulated from, the ceiling. (This can be supplied by Ampetronic).
If the ceiling is not metal, or a suitable hidden location can be found inside a metal
lift car, normal insulated wire of 2.5 mm² or 4 mm² can be used.
The connection from the loop to the equipment should be made using two 2.5 mm²
wires twisted together.
INPUTS
AUDIO SYSTEM
Power Supply
Supply Voltage Range: 90V-264V (mains)
Freq Response:
100Hz to 5kHz ±1.5dB relative to 1kHz at low
Connector: Fused screw terminal
level, measured as loop current with no metal
Power Consumption: 230V AC into rated
2
loss correction
load, 1.5mm solid core or untinned
stranded wire.
Compression:
Fuse: T 1A L (120V)
Time constants optimised for speech
Fuse: T 630mA L (230V)
Power Consumption (230V): 12W (110mA)
AGC:
continuous pink noise, 25W (190mA)
Dynamic Range: >36dB
continuous sine, 3.25W (<60mA) quiescent
Control: By adjusting input level/gain
Indication: LED on PCB
Indication: LED on PCB
Inrush: <±25A
pk
MLC (Metal Loss Correction):
Inputs 1 & 2
0 dB to 3dB / Octave boost.
Connector: Wago 264 Cage Clamp for 0.78
Correction: Adjustable
2
- 2.5mm solid core or untinned fine
stranded wire
PHYSICAL
Dimensions:
Line level
Rated source Impedance: 1.8 k
W
differential
Input Isolation: 1500 V
Rated source EMF: (
Sensitivity
) -16dBu
for
full output
Overload: >+22dBu
SnR: >90dB
Adjustment: Level control, per channel
Standards:
Meets relevant CE, EMC and safety
OUTPUTS
standards.
IEC 60118-4 AFILS
Loop Output
Connector: Wago 264 Cage Clamp for 0.78
2
Environment:
- 2.5mm solid core or untinned fine
stranded wire
IP22 <90% relative humidity, -20 to +50°C
Compliance Voltage: 1.1V
rms
(1.6V )
pk
(battery float life derates by 4% per °C above
Max output current: 11A
rms
25°C)
Rated time for delivery: 1min
Rated temperature limited output current
Please contact Ampetronic if you need further
(pink): 6A
rms
assistance.
Rated THD: <1%
Output Impedance: >1
W
Current Adjustment: Full Range
Current Indication: LED indicates >3A
rms
Loop Impedance
0.1
W
to 0.2
W
, 0.14
W
reactive at 1.6kHz
Rated load: 9uH, 0.1R
Weight: 3kg
Length: 366mm
Width: 158mm
Height: 49mm
TECHNICAL SPECIFICATIONS
TROUBLESHOOTING
For correct operation, you should have the following LEDs illuminated
Power (Green)
Compression (Green) only whilst audio signal is applied to an input
Loop Current (Yellow) only at peaks of audio signal
Power LED not illuminated
Battery discharged and external AC mains supply off - turn on external AC mains
supply to charge battery and to operate unit.
Compression LED not illuminated at any time
No inputs connected - connect an input as described above
Relevant IN control not turned up far enough - adjust control as appropriate
Input signal level too low - check that input signal is >120mVrms for Lo-Z speaker
inputs.
Current LED not illuminated (even at peaks of signal)
Loop not connected or open circuit - See above for correct loop location, and
check loop continuity using a resistance meter. Value should be under 300mW.
Relevant IN control not turned up far enough - adjust control as appropriate
No field received in the loop area
If Current LED is illuminated at peaks of signal, but no field is received in the loop
area, then the loop is installed in the wrong place or there is a short circuit
between the ends of the feed cable. Read the 'Loop design' section above to
confirm loop design.
If Current LED is not illuminated, see previous troubleshooting options for a
solution.
