Reliable Surge Protection for RJ11 Telephone and Telecom Lines
LY21-1 is an inline RJ11 telephone surge protector designed to help prevent transient overvoltage from entering sensitive telecom equipment through audio and telephone lines. It is suitable for telephone systems, fax machines, modems, private branch exchanges, emergency telephones, and relay communication circuits.
Inline protection for RJ11 telephone and audio signal lines
45V, 130V, and 170V operating-voltage options
Up to 2Mbps transmission with ≤0.2dB insertion loss
Compact IP20 design for telecom and control cabinets
Suitable Applications
LY21-1 is suitable for RJ11 telephone and low-frequency audio communication lines that require protection against lightning-induced and switching transient overvoltage.
Telephone Systems
Protects telephone handsets, office telephone lines, PBX extensions, and telecom terminal equipment.
Fax & Modem Lines
Helps protect fax machines, dial-up modems, communication terminals, and analog data equipment.
Emergency Telephones
Suitable for emergency call stations, roadside telephones, help points, and public safety communication lines.
Relay & Telecom Lines
Protects relay communication, audio control, telecom exchange, and low-frequency signal circuits.
FAQ
Common questions about LY21-1 RJ11 telephone line surge protector selection and installation.
What is the LY21-1 RJ11 surge protector used for?
LY21-1 is installed in series with an RJ11 telephone or audio communication line to help prevent transient overvoltage from reaching telephone, fax, modem, PBX, and emergency communication equipment.
Which voltage version should be selected?
Select the 45V, 130V, or 170V operating-voltage version according to the normal and ringing voltage of the protected telephone or communication line. The corresponding maximum continuous voltages are 60V, 150V, and 185V.
Can LY21-1 be used for fax machines and modems?
Yes. It is suitable for fax equipment, analog modems, SPC exchanges, relay lines, and similar devices using RJ11 telephone or audio communication connections.
Will the protector affect telephone or data transmission?
The listed maximum transmission rate is 2Mbps and the insertion loss is no more than 0.2dB. Compatibility should still be checked against the actual line voltage, signal type, ringing voltage, cable length, and connected equipment.
How should LY21-1 be installed?
Install it inline between the incoming RJ11 line and the protected equipment. Place it as close as practical to the protected device and keep the grounding connection short and direct where required.
What should be confirmed before ordering?
Confirm the normal line voltage, ringing voltage, RJ11 pin configuration, number of protected conductors, signal type, load current, grounding method, installation direction, and required surge withstand level.
