Signal SPD

Electronic devices are always threatened by power surges and transients caused by power failures or nearby lightning strikes.
Signal SPD surge protection device is born to protect electronic devices in automatic control systems.

The surge protection equipment can provide surge protection for field equipments such as sensors, transmitters, flow meters, solenoid valves, thermocouples, thermal resistance, devices with RS485 or RS232 interface and for I/O interfaces such as Al, AO, Dl, DO, Tl, Pl in PLC, DCS, FGS, ESD control systems.

Signal data surge protector is widely used in petrochemical, gas, environmental protection and new energy industries.

Chenzhu also provides signal surge protector in intrinsical safety circuits that meet the same design and structural standards as intrinsic safety equipment, which requires certification and approval of them.

Signal SPD
Intrinsic Safety 5V Signal SPD
Intrinsic Safety 24V Signal SPD
Signal SPD For 5V
Signal SPD For 24V
FAQ of Signal SPD
How do I choose a signal SPD?-
CHENZHU SPD for signal is mounted by DIN rail. It can be selected from informations below.

1. Type of the signal

According to the signal type, we can get the information of the signal voltage, so as to determine Uc.

For example, normally,

AI，AO： 24V，

DI，DO： 24V，

RS485， TC：5V，

RS232：12V

RTD：5V.

2. Rated current IL

Since SPD for signal is normally installed in range, operating current will go through SPD. If operating current is bigger than IL of SPD, SPD will be damaged. Normally IL will be big enough. For 3-wire, 4-wire carrier current transmitters and DO signals which have higher power consumption, IL need to be checked.

3. Number of wires to be protected

Select 2 wires, 3 wires, 4 wires accordingly.

4. Is intrinsically safe explosion-proof required?

Yes——select intrinsically safe SPD;

No——select non intrinsic safety SPD.

How to judge if SPD is functional?

SHANGHAI CHENZHU INSTRUMENT CO., LTD. is a very established provider that specialises in automation safety. We provide automation safety, signal arrester, signal surge protection device, intrinsically safe temperature transmitter and etc.