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Product name: RS485,232 telecom communication interface protection PTC thermistor

Item: MZ31 series

RS485,232 telecom communication interface protection PTC thermistor

Brief Introduction:
MZ31 series MZ9,MZ6 type PTC thermistors are protection components used in RS485,232 communication interface evolved out of the program-controlled security unit used for SPC exchanges.This PTC tandem connection in RS485,232 communication interface, which can prevent damage to interface of telecommunication line effectively caused by importing 220 V electric supply due to accident broken or man-made damage, can also reduce influence to the interface of communication lines caused by lightning induction.This product has features of small steady resistance,low rated current, high voltage endurance capability and fast response etc., is economy applicable protection choice of RS485,232 communication interface.

Product Application:
RS485, 232 communication interface protection

Working principle:
Automatic meter reading is becoming increasingly popular in electronic power meters, this technology provides a communications port to the power meter, allowing it to be read electronically in a remote way. RS-485 is a simple, cheap, reliable communications specification that is well suitable for automatic meter reading. The PTC thermistor provides overcurrent and overvoltage protection in the circuit.For example if one of the RS-485 wires gets shorted to the main power line (eg, 220/380V), DXM’s PTC thermistor is specially designed for RS-485 interface protection.

As indicated in Fig 2 as below,when circuit is in the normal state, the current through PTC is lower than the rated current and PTC is in the normal state with small resistance value,which will not affect the normal operation of the protected circuit such as primary and secondary loops of the voltage transformer. In case of some trouble in the circuit and the current is bigger than the rated current,the PTC will become hot quicklyand present high resistance value, which sets the circuit relatively “off” to protect the circuit from damage.After the trouble is removed, PTC will automatically restore its low resistance state and the circuit will resume normal operation.

1.Small steady resistance ;
2.Low rated current;
3.High voltage endurance capability;
4.Fast response;
5.economy applicable protection choice of 485 communication interface;

Dimension(Unit: mm):

Marking of Part Number:

1.Series: PTC thermistors for overcurrent and overload protection
2.Type:1-disc,2-encased,3-pin form-coating,4-pin form non-coating,5-SMD
3.Type:A-general, B-compount, C-moduie
4.Chip size: 8-Φ8mm,9-Φ9mm
5.Curie temperature: F-50℃       H-75℃       N-105℃        K-125℃
6.R25 resistance: 6R0-6Ω     6R5-6.5Ω        121-120Ω
7.Resistance tolerance: K+/-10%        M+/-20%         H+/-25%         N+/-30%
8.Greatly voltage:420-420V
9.Wire shape: S-Straight, A-Axis formed, U-In-formed
Specification&Part No.:

Remarks:Except for the reference size and parameter above,different electrical parameter and encapsulation mode can be custom made per client's requirement.
You can send us required specifications to info@dxmht.com or provide reference samples to our factory office:
And then samples&orders can be custom made per your requirement.