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Model 298 ADA-Compliant Emergency Telephone
Pub. 42004-304A
f:\standard ioms - current release\42004 instr. manuals\42004-304a.doc
06/02
TROUBLESHOOTING
Symptom
The emergency telephone attempts to execute the auto-dial sequence but is unable to complete this function.
The telephone attempts to reset itself and start the auto-dial process again. This may be detected by
hearing the Hi/Lo splash tone 3 or 4 times before the telephone disconnects.
Definition of Problem
The emergency telephone is not receiving sufficient current from your PBX or CO line to initiate the auto-
dial sequence. The typical telephone line provides 48 V dc across the tip and ring when the telephone is
activated. The introduction of 24 V dc PBXs into the marketplace has resulted in lower loop current than
the 48 V dc PBXs. A low current situation may also be the result of long cable runs, even in the 48 V dc
systems. The emergency telephone typically requires a minimum of 28-30 milliamps of current for proper
operation due to the on-board microprocessor.
Solution
GAI-Tronics telephones are capable of 48 V dc to 24 V dc conversion by adding a jumper. This procedure
will automatically mute the speaker function during the first few seconds of dialing (no tone is heard over
the speaker during the mute period), reducing the amount of current required to perform line seizure and
auto-dial sequence activation. This solution is suitable for both 24 V dc systems and 48 V dc systems with
long cable runs. Please note that “long line” or “off premise extension” cards may be necessary for the
PBX to provide the appropriate loop current for long cable runs.
ENABLING 24 VOLT POWER MODE
1.
Open the telephone by removing the 6 tamper-resistant screws on the front cover of the telephone.
2.
Being careful not to break any wires, gently pull the telephone out of its box and flip it face down.
3.
The telephone is connected to the telephone line with an RJ11 connector located in the back box.
Disconnect the telephone from the telephone line by unplugging the RJ11 connector.
4.
Remove the 4 Phillips screws holding the black cover over the circuit board, and remove the cover.
A jumper clip is provided within the packing box of the emergency telephone inside a small envelope
marked “Do Not Discard.” Install the jumper clip over pins 1 and 2 in connector J7 on the main circuit
board. Refer to Figure 6 for the location of J7 and the pins on which the jumper must be installed. Refer
to Figure 4 for the 24 V mode installation details when a key switch is installed.
5.
Reinstall the black cover over the circuit board. The cover fits two ways. If installed correctly, holes
in the cover allow access to the microphone and speaker adjustments. The smooth side of the black
cover faces away from the circuit board.
6.
Using the modular wall jack, connect the telephone to the telephone line by plugging the RJ11
connector into the back box.
7.
Being careful not to break or pinch any wires, insert the telephone back into the back box.
8.
Close the telephone by re-installing the 6 tamper-resistant screws into the front cover.
9.
Verify the telephone operates properly.
Note:
It will be necessary to program the telephone as indicated in this manual if not programmed
previously. If programming was completed prior to determining low current operation was required, no
additional programming will be necessary.
