External signaling device connected to the LEF Series.

Difficulty Level

2 – Easy/Moderate – component connection to external points

Components Required

1. RY-AC/A : external signaling relay
2. External signaling device and its own power supply (not supplied by Aiphone)

Instructions

If only one sub station is to have the capability of activating the external device:

1. Connect white wire of the RY-AC/A to the number terminal on the master station of which the door station is connected. Connect the red of the RY-AC/A to the “+” of the LEF master station. Connect the black wire of the RY-AC/A to the “-“ of the LEF master station.
2. The yellow leads of the RY-AC/A will provide a normally open dry closure whenever there is a from the door station. Connect this contact in accordance with instructions provided with your external signaling device and power for the external device.
3. *If all sub stations need to activate the external device, connect the white wire of the RY-AC/A internally as shown on the schematic (changes difficulty rating to a level 4). The red, black and yellow wires of the RY-AC/A connect as above.

If more than one sub station is in the system, and it is required that all sub stations activate the external signaling device, connect the white wire to internal point. See following schematic.

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Increase LED timing circuit.

Difficulty Level

3 – Moderate – removal or replacement of internal components.

Components Required

1. Capacitor:
   • 220 µfd, 16V, ~2 minutes
   • 470 µfd, 16V, ~4 minutes
   • 1000 µfd, 16V, ~5 minutes

Instructions

1. Remove and replace C3 on the main PC board of the LEF Series master station with a different value capacitor to achieve the desired LED timing length.
2. LEDs will stay illuminated for the duration of the timing circuit from the moment the last sub station places a call.

LEF Master Stations

Locate and replace capacitor C3. Change value to a higher level to reach the desired timing circuit length.

• 220 µfd, 16V, ~2 minutes
• 470 µfd, 16V, ~4 minutes
• 1000 µfd, 16V, ~5 minutes

LEF-10C Master station

Locate and replace capacitor C3. Change value to a higher level to reach the desired timing circuit length.

• 220 µfd, 16V, ~2 minutes
• 470 µfd, 16V, ~4 minutes
• 1000 µfd, 16V, ~5 minutes

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Reducing RF interference when too close to a radio station tower, or other source emitting RF noise.

Difficulty Level

4 – Moderate/Hard – internal connection or component addition.

Components Required

1. Choke coil: 180 µH inductance.
2. Capacitors:
   • 0.01 µfd, 25V
   • 0.02 µfd, 25V
3. AC plug adaptor: 3-prong to 2-prong type.

Instructions

1. Install the 3-prong to 2-prong adaptor on PS-12C power supply.
2. Install choke coil and capacitors as shown on schematic diagram.
3. Cut the circuit as illustrated on the schematic diagram.
4. If the RF interference is not reduced to an acceptable level, shielded cable will need to be installed to further reduce the interference. Depending on the severity of the interference, the above suggestions may or may not eliminate the interference.

LEF-3

LEF-5/10/10S

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Modern intercom systems, with solid state circuitry, are much more efficient and compact than older systems with relays, coils, and vacuum tubes. Unfortunately, they are also more susceptible to malfunction or failure due to transient overvoltage, such as lightning and AC power surges.

Lightning

Lightning overvoltage is caused by a strike of lightning to or near a conductor or shield of an intercom cable. Shielded wire does not provide complete protection against lightning damage. When lightning or other voltage spikes flow on the shield of a cable, voltage is induced between the internal conductors and the shield. The amount of induced current depends on the resistance of the shield material and construction of the cable.

AC Power Surge

A typical example of power surge is the voltage spike that occurs when heavy duty generators are powered up, or when surges occur on the main electrical system. Lightning can also create power surges in AC power lines. Ranging in amplitude from harmless amounts just above normal voltage to several kilovolts. If the intercom cables are run with the AC power lines (which is strongly discouraged), the AC power surge can bleed over into the intercom cables.

About Metal Oxide Varistors

Voltage spikes affect all semiconductors, which are intolerant of voltage transients in excess of their ratings. Even a slight amount of excess voltage can cause a semiconductor to fail or be degraded enough to shorten its useful life. Most lightning damage to intercom systems is caused by lightning opening or shorting semiconductors. A voltage clamping device such as a metal oxide varistor (MOV) is recommended to absorb the voltage spike before it enters the intercom unit. An MOV has the best volt-ampere characteristics, energy absorption, and peak current capabilities compared to other voltage clamping devices. The specifications for an MOV used on an Aiphone system are as follows:

• Continuous DC voltage: 50 ~ 100 V
• Transient Peak Current: » 250 A
• Maximum Clamping Voltage: 100 ~ 150 V

One MOV is to be installed between each wire in the cable and an earth ground for each intercom unit. In lightning-prone areas and where power surges are possible, surge protection should be installed.

Modification

Prevention of AC power surge and/or lightning damage.

Difficulty Level

2 – Easy/Moderate – component connection to external points.

Components Required

1. SA-1: surge arrestors, one for every two terminals being protected.
2. Surge sensitive power strip.

Instructions

1. Plug all system power supplies into surge sensitive power strip, then plug the strip into an AC outlet.
2. Wire SA-1s on all intercom terminals as shown on the diagram, with output side connected to an earth ground.
3. SA-1s are recommended to be installed on master stations only and are not necessary on remote stations.

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Eliminate incoming call tone from sub station at a master station.

Difficulty Level

3 – Moderate – removal or replacement of internal components.

Components Required

N/A

Instructions

• LEF-3/3C: remove transistor TR7.
• LEF-5/5C: remove transistor TR7.
• LEF-10/10S: remove transistor TR8.
• LEF-10C: remove transistor T7.

LEF-3

LEF-5

LEF-10

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Installing a volume control on an LE Series sub station.

Difficulty Level

5 – Hard – circuit creation and internal addition.

Components Required

1. Variable resistor: 50 ~ 250 Ω, 1 W
2. Resistor: 33 Ω, 1 W

Instructions

1. Install components as shown on the diagram.
2. No physical provisions are made on the sub station for the addition of a volume control. Chassis modification is required.

LE-A

LE-AN

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LED monitoring indicator on an LE series sub station. This modification allows users to know that their station is being monitored by a master station.

Difficulty Level

5 – Hard – circuit creation and internal addition.

Components Required

1. Resistor: 1K Ω, 0.25 W
2. LED: general purpose

Instructions

1. Run two extra wires to each sub station requiring the modification. (Only one extra wire is required when using LE-C, LE-CN, or LE-DL.)
2. Install LED and resistor as shown on diagram.
3. When a master station selects that sub station, the LED will illuminate.
4. No physical provisions are made on the sub station for the addition of an LED. Chassis modification or external mounting is required.

Diagram

Notes:

• Inside the sub station, install the general-purpose LED and 1K Ω resistor as shown above.
• Since there is no designated location for placement of the LED, either modify the chassis of the sub station or mount the LED externally.
• The LE-C, LE-CN and LE-DL already have the “+” wire connected to them. Only the “K” wire will need to be added with those models.

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Tape recorder output on LEF master station allowing conversation from both sides to be recorded.

Difficulty Level

5 – Hard – circuit creation and internal addition.

Components Required

1. Resistors:
   • Two 10K Ω, 0.25 W
   • One 10~15K variable resistor
2. Capacitor:
   • Two Aiphone model NP-25V (33 µfd, 25V, non-polarized)

Instructions

1. Install components as shown on the following schematic.
2. This modification will allow a tape recorder to record both sides of the conversation while the master is communicating with another station.

LEF-3

LEF-5

LEF-10

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Various relay contacts using the LEF Series.

Difficulty Level

2 – Easy/Moderate – component connection to external points.

Components Required

1. RY-AC: external signaling relay
2. RY-PA: 12V DC normally open relay

Instructions

1. See following diagram for options on closures available.

External Signaling

Selective Door Release

Camera Control/Light Activation

Both Door Release and Camera Control/Light Activation

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Single call sub station to receive All Call and Background Music (BGM).

Difficulty Level

1 – Easy – wire connection only.

Components Required

1. Capacitor: Aiphone model NP-25V
   (33 µfd, 25V, non-polarized).

Instructions

1. Install capacitor in series between the number terminal of the master station and the BGR-10A/BG-10C as shown on the diagram.
2. All Call and/or BGM require either the BGR-10A (with PS-2410A) or the BG-10C (with PS-12F) to be installed in the system.
3. Aiphone master stations with All Call activation capability are:
   • LEF-3C
   • LEF-5C
   • LEF-10C
   • LEF-10S
   • LEF-1C
4. LE-C/CN sub stations do not require the capacitor.

Operation

This system allows communication from the LEF-10C master stations to all other stations in the system. The sub stations can call the master stations by tone and communicate hands-free. All stations can receive music and All Call announcements. Only the LEF-10C’s can initiate All Call announcements and answer the door station.

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