Troubleshooting Pacific Electronics Apartment Intercom System
Entire System Dead
Check for 16 VAC at transformer secondary and 120 VAC at transformer primary. If LED is illuminated, review field wiring and perform direct test using one of the apartment stations to eliminate field wiring.
Check wiring to terminals C and T, and check whether wiring to entrance panel speaker is shorted or open. Suite station can be swap tested with another working unit.
Check wiring to terminals C and PT, or for short between terminals C and T. Check to see if wiring to entrance panel speaker is shorted or open. Suite station can be swap tested with another working unit.
No Door Operation
Check wiring to door release for shorts and opens, or for defective door release. Confirm that shunts are properly set for door release type and that connections to appropriate output have been made. Check wiring to terminals C and D, or PDR and SC (depending upon suite station type).
No Call Tone
Check wiring to terminal B or BW to entrance panel, related entrance panel call buttons, and suite station SIG terminal. Suite station can be swap tested with another working unit.
Excessive Hum or Distortion
Check whether wiring is installed too close to electrical wiring or electrical devices; amplifier installed too close to transformers or other electrical devices; twisted pair wiring not used as required; or amplifier voice volume set too high.
Connect G terminal from amplifier to electrical ground. Note: This connection is not shown on the wiring diagram, since the situation is not always improved by adding it. If the problem persists, consult the factory or service representative.
Oscillation (feedback or howling)
Reduce the voice volume until oscillation is eliminated. Check the entry panel speaker for 45 ohms.
Signal Flow and Theory of Operation for AF1000 Amplifier and Apartment Intercom System
The following example describes an apartment intercom system using a AF1000 in conjunction with a 4-wire suite station. Refer also to Figure 5 on page 8.
Pressing a suite station call button on the entrance panel routes the call tone from the B or BW terminal on the AF1000 to the SIG terminal (tone in) on the associated suite station. This signal then passes through the speaker and returns to the AF1000 via the C terminal (audio common). If the warble tone is in use and the entrance tone feature is active, the tone will also be heard through the entrance panel speaker when the call button is pressed.
Pressing the talk button at a suite station connects the suite station’s internal speaker to terminals C and T of the AF1000, which serves as an audio input to the amplifier. The audio is then amplified and sent to terminals SC and S, which are connected to the entrance panel’s speaker (speaker mode).
Pressing the listen button at a suite station connects the suite station’s internal speaker to terminals C and PT (4W) of the AF1000, which serves as an audio output from the amplifier. This allows the suite station to receive the amplified audio being received by the amplifier on terminals SC and S from the entrance panel speaker (microphone mode).
Pressing the door button at a suite station creates a closure between terminals C and D on the AF1000. This state is sensed by the amplifier and causes the door release to be activated. This state is also triggered by shorting terminals 1 and E as is typically done by a postal lock.