Transcript bonded - MacMate

ADT490
Panel Theory
System Power Supply Grounding
‣ Circuit separates positive / negative from
Ground
‣ Ground fault - resistance to ground ≤ 10 kΩ
‣ System power supply
‣ Line - black
‣ Neutral - white (return)
‣ Ground - green
‣ Exterior components bonded to Ground
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Power Supply
‣ Output 27 to 30 Vdc
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Power Supply Fault Analysis
‣ Power on - how do we know?
‣ Disconnect or breaker station - looking for?
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Power Supply Checklist
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Power Supply Checklist 2
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Battery Charger Concepts
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2 x 12 V or 4 x 6 V batteries
To charge requires 27.4 to 28 V
must be recharged to 70% within 12 hours (ULC)
5 to 35 mA - float Charge
Fast Charge - larger
Battery Condition Monitor
Ammeter in Series to check the Charge rate (A)
Can check power supply with DC & AC Voltage
Measurements
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Battery Charger Concepts
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Electrical Supervision
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small current though an EOL Resistor
no current though an EOL Capacitor
Power resistors
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approximately 200 Ω
1 volt each
about 2 W
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Electrical Supervision
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Detection - Open Circuit
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EOL Resistor Function
‣ Limits current through wiring
‣ Regulates the voltage in the circuit
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EOL Capacitor Function
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Siemens System 3 or MXL
EOL Capacitor
Blocks DC
Smooths ripple voltage
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Detection Circuit with EOL
Capacitor
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EOL Capacitor Waveform
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EOL Capacitor Waveform
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Locating Faults
‣ Voltage on open EOL Capacitor circuit is 20.5V
(System 3) & 21.5V (MXL)
‣ Voltage before the break
‣ 0 V after the break
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EOL Relays
‣ Mostly used on security systems or
‣ 4 wire devices
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EOL Relays
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Wiring Architectures
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Class B
Class A
Split Class B
Tee-Tapped
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Class B Wiring - Placement or
Location Supervised (87%)
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Class A Wiring - Placement or
Location Supervised (8%)
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Class A Wiring - Greater Reliability
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Class B Wiring with Tee-Taps
‣ Tap is unsupervised
‣ Reason each device is checked for open - S537
‣ Some vendor use twice EOL size for main run and
single tap
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Class B Wiring with Tee-Taps
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Addressable Loop - no EOL
‣ A fault cannot disable more than 1 Zone
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Signal Circuit Supervision
‣ Terminal may indicate polarity in alarm - not always
‣ 24 VDC can be as low as a few volts
‣ Shorts causes a circuit Trouble
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Signal Circuit Alarm Operation
‣ Device could be reverses - rings supervision not alarm
‣ Don’t exceed 85% of Current - Why?
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Class A Signal Circuits
‣ Class A good for opens
‣ Not good for shorts - Why?
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Speaker Circuits - Supervision
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Speaker Circuits - Alarm
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Speaker Circuits - Alarm
‣ 25 Vrms 20 and 40 mA for speaker + 5 mA for EOL
‣ 70.7 Vrms 7.1 and 14.1 mA for speaker + 7.1 mA for
EOL (equivalent to 1/2 W Speaker)
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Split Speaker Circuits
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Split Speaker Circuits
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Telephone Circuits
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Improperly Connected Signals
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end
of
Presentation
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