Model OVP-02

Hagner OVP-02 Overvoltage Protection


The Hagner OVP-02 Overvoltage Protection has been designed to give extra protection to the Hagner TLS-420 Tunnel Photometers which are mounted in areas where there are risks from over voltage and/or transients, caused by an unstable power supply or lightning strikes in the surroundings.
There are some areas where the Hagner Tunnel Entrance Photometers are at risk from over voltage and/or transients on the power net and transients on the signal cable, which may be caused by an unstable power supply or lightning strikes in the surrounding area. Both incidents can, if they are powerful, damage the electronics in a Photometer. (The instruments are provided with VDRs but these give only a very limited protection.)
It is therefore recommended that Photometers mounted in such areas are connected to over voltage protection, i.e. Hagner OVP-02, which will greatly reduce the risk for damage.
Please note that 100% protection can never be guaranteed.


OVP-02 consists of a water proof plastic housing (IP67) containing an over voltage protection for the input side (Weidmüller PU DS 230V/16A) and an over voltage protection for the output side (Weidmüller MCZ OVP CL 24VDC 0.5A). The housing should be mounted as close to the tunnel photometer as possible to minimize unprotected stretches of cable. (A separate OVP-02 can be used for protecting a PLC used together with the photometer.)
The input protection is provided with a light diode, emitting green light as long as the protection is functioning and undamaged, and an output which for instance can be connected to a PLC to indicate if the protection has been exposed to over voltage or a transient. The protection should always be exchanged after it has been exposed.
The output protection will stop minor transients and reset to stand-by position. Major transients will normally be stopped but will damage the protection, which in turn causes the output signal to fall to 0 mA. The protection must then be exchanged.

Technical data


Weidmüller PU DS 230VAC 16A and
Weidmüller MCZ OVP CL 24VDC 0.5A
(Weidmüller web site:

 Protection rate

Mounting brackets
Temperature range
Cable entries

APC polyester

IP 67

230 x 147 x 147 mm (incl cable entries and mounting brackets)
1.4 kgs
CC200 x CC90 mm for M6 screws

-50ºC - +70ºC (peak +120ºC)

2 pcs PG13.5
2 pcs PG9
1 pc PG9 (blind plug for alarm function)