FATECH Surge Protector Selection Guide for Signal Lines
This guide offers professional recommendations covering applicable standards, key parameters, scenario-based selection and recommended configurations.
I.Confirm the Protected Object First
1. Interface:RJ45(Cat5e/Cat6/Cat6A)
2. Power Supply:PoE(IEEE 802.3af/at/bt)
af:15.4W,44–57V
at:30W,50–57V
Bt:60/90W(PoE++),52–57V
3.Protected Devices:Outdoor cameras, wireless access points(AP),switches,network video recorders(NVR),etc.
4.Application Environment:Outdoor poles/rooftops–high lightning risk; Indoor equipment rooms–moderate lightning risk
II.Core Parameter Selection(by Priority)
1. Maximum Continuous Operating Voltage(Uc)–Top Priority
The standard PoE voltage is 48V DC.Uc≥57-64V DC is recommended to provide sufficient margin and prevent false tripping caused by normal voltage fluctuations.
2.Voltage Protection Level(Up)
Line-to-line(signal):≤30V
Line-to-ground(signal):≤300V
Ensure the rear Ethernet port(PHY chip)is protected from breakdown.
3.Discharge Current In/Imax(8/20ÎĽs waveform)
Nominal discharge current(In):≥2kA
Maximum discharge current(Imax):
Indoor&general scenarios:≥3kA
Outdoor,pole-mounted&high lightning risk areas:≥10kA
4.Bandwidth&Insertion Loss(Guarantee error-free Gigabit transmission)
Bandwidth:≥250MHz(mandatory for Gigabit network)
Insertion Loss(IL):≤0.5dB@100MHz.Higher loss leads to packet loss。
5.Protected Wire Pairs(Full protection required)
All four wire pairs(1/2,3/6,4/5,7/8)for data and power supply must be protected. Products only protecting 1/2 and 3/6 pairs are low-end 100Mbps models,not applicable for Gigabit network or PoE++.
6.Response Time
≤10ns
7.Enclosure&Installation
Outdoor models:IP65 waterproof rating,equipped with grounding terminals
Indoor models:DIN 35mm rail mount or wall-mounted type
III.Scenario-based Selection(Direct Reference Configurations)
1.Scenario A:Pole-mounted Outdoor Cameras(Most Common)
Recommanded model: FS-RJ45W/PoE-1000
Type:Integrated RJ45+PoE,IP65 waterproof
Uc:≥57-64V DC
Up(line-to-line):≤150V
In/Imax:2kA/3kA
Bandwidth:1000MHz;Insertion Loss≤0.5dB
PoE Compatibility:Supports af/at(30W);PoE bt(60W)is preferred
Installation:Install right before the camera Ethernet port with proper local grounding
2.Scenario C:Indoor APs&Terminals(Low Lightning Risk)
Recommanded model:
| FS-RJ45D/PoE-1000 | FS-RJ45/PoE-1000A |
 |
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Type:Compact DIN rail mount or desktop type
Uc:≥57-64V DC
In/Imax:2kA/3kA
Other parameters follow the above requirements
IV.Mandatory Compliance Standards(Avoid Non-standard Products)
Domestic Standards:GB/T 18802.21-2016,GB 50057
International Standards:IEC 61643-21,EN 61643-21
Certification:CE
V.Summary of Recommended Models
Indoor Use:FS-RJ45D/PoE-1000(DIN rail mount), FS-RJ45/PoE-1000(wall mount)
Outdoor Use:FS-RJ45W/PoE-1000
VI.Main Parameters of Signal Surge Arresters
1. Uc: It is the maximum voltage on the SPD in the defined non-conductionve state which ensure the transmission characteristic is regained after response and discharge.
2. Transfer rate:it is the upper limit data transmission rate when SPD connected to the transmission line of Signal system, and it do not influence the transmission of the system.
3. Return Loss: indicates at high-frequency applications, how many rates of the “forward” wave are reflected at the protective device. It is a direct measure of rating the adjustments of the protective device to the surge impedance of the system.
4. Insertion loss: At an indicated frequency, the insertion loss of a SPD is defined via the relation of the voltage value at the installation site before and after the insertion of the SPD.
5. Insertion Loss(dB)=-10log(Pout/Pin)
6. Up: Parameter characterizing surge arrester operation by the level of voltage limitation between its terminals and which is selected from the list of preferred values in the standard.
