Type 1 Surge protectors

Many technologies exist for type 1 surge protector (designed to be installed where a direct lightning strike risk is high, especially when building is equipped with external lightning protection system) :

Multi-MOV
Multi-MOV + Gas tube
Spark gap + Trig

CITEL had first developped the technology " Multi-MOV ", and then has developped a new technology " Multi-MOV + Gas tube " called VG technology.

CITEL references are :

DS150VG : Type 1 surge protector one pole, 15 kA.  Click here for more info
DS250VG : Type 1 surge protector one pole, 25 kA. Click here for more info
DUT250VG : Compact Type 1 surge protector 3 phase + neutral, 25 kA (new).

Advantages of VG technology

1.  Excellent protection level (Up) and impulse current (Iimp) in one single module

Such performances can only be obtained by a combination of Type 1 protection and Type 2 protection. 

Advantages "VG"
- Equivalent to type " 1+2 ".
- Strong efficiency.
- Compact. . 

2. No follow current 

Compared to "spark gap" technology, "VG" technology do not create follow current.

Advantages "VG"
- Reduce the risk of activation of the switch gear during a strike.
- Best behaviour possible on AC network (no follow current and no leakage current) and very low residual voltage during strike.
- Easy installation.

All components of VG surge protectors (MOVs and gas tube) can support 10/350 µs impulse current in 15 or 25 kA which is not the case for technologies based on " spark gap + trigger " that integrate in the trigger many small components.

Advantages "VG"
- Higher reliability.
- Longer lifetime.

4.  Status indicator 

The VG surge protector includes a disconnection mechanism fault indicator for remote signalling. For technologies based on trigger, fault indicator when they exist do control only the status of the command circuit and not the main protection device, the spark gap.

Advantage "VG"
- Easy maintenance.

5.  Gas tube 

The VG surge protection include a gas tube especially manufactured by citel. Compared to spark gap, gas tube is not sensitive variation of humidity or atmospheric pressure.

Advantage "VG"
- Higher reliability.

6.  No stress on MOVs   

In VG surge protectors, gas tube and MOVs are connected in serial. MOVs do not support any voltage (except during strike) from the network. Compared to surge protectors based on MOVs only, that support AC voltage permanently, MOVs in VG surge protectors will not be affected by AC voltage.

Advantage "VG"
- Higher lifetime.