NVR User Manual
17
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To protect the host against overload, read the relay parameters on the alarm output side in the
following table before cable connection.
Model: HFD3
Contact material
AgNi
Rated switching capacity
30V DC 2A, 125VAC 0.5A
Maximum switching power
60W/62.5VA
Maximum switching voltage
220VDC, 250VAC
Rated values
﴾Resistance load﴿
Maximum switching current
2A
Between contacts with the same polarity
1000 V AC, 1 minute
Between contacts with different polarities
1500 V AC, 1 minute
Insulation
Between contacts and coils
2000 V AC, 1 minute
Surge voltage
Between contacts with the same polarity
1500 V AC ﴾10 x 160 us﴿
Connection time
4ms max
Disconnection time 4ms max
Mechanical
100,000,000 times
Service life
Electrical
100000 times ﴾30 V DC, 2 A﴿
Operating
temperature
-
40ºC to +85ºC
Parameters of relays on the alarm output side
2. Alarm output connection diagram
Generally, the alarm output terminal is disconnected. It is closed when an alarm needs to be reported. It
does not provide voltage output, and external power supplies are required to ensure proper operating of
external speakers, lights, and alarm devices. As shown in the following figure, the independent power
supply terminal is connected to the positive and negative terminals of the external power supply.
Alarm device
NVR alarm output
NO/NC
COM
Independent
power supply
Precautions for alarm output connection:
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Do not connect the alarm output terminal of the NVR to high‐power loads. ﴾For details, see the relay
