Schaltbau’s new compact bi-directional DC contactors C800 series for automotive applications in the modern mobility industry. They switch high power in a small space and have a making capacity of up to 4,500 amps. The contactors permanently carry up to 500 amps; in the event of a short circuit, even 6,000 amps may flow for 20 milliseconds without the contacts welding. Thus, the contactor retains its full function to switch large powers when required, for example up to 1,200 amps and 450 volts – regardless of the direction of the current.
This makes C800 series contactors ideal for use in the Battery Disconnect Unit (BDU) of modern e-vehicles. The BDU connects the high-performance battery with the electrical components of the drive train. And it performs an important safety function: in the event of danger, it disconnects the high-voltage battery from the high-voltage grid. In the event of thermal overload or a short circuit, the electrical drive train is thus reliably galvanically isolated from the battery.
Small dimensions – great performance! Nevertheless, all the air gaps in the contact area have been generously dimensioned. The rated insulation voltage is 1,000 volts.
The arc chamber of the C800 is made of plastic. This is efficient and saves weight.
All versions of the C800 can carry up to 500 A continuously. The short-time current carrying capacity Icw is a maximum of 6,000 amperes for 20 milliseconds.
The C800 can switch on a current of up to 4,500 amps. High contact forces and burn-off resistant silver contacts favour the excellent breaking capacity.
All versions of the C800 can reliably separate high currents and voltages when required, regardless of the direction of the current. These properties are achieved by the special arrangement of blowout magnets and arc chamber, burn-off resistant silver contacts, high contact forces and generously dimensioned air gaps in the contact area.
The C800 contactors have an integrated auxiliary contact with mirror contact function according to IEC 60947-4-1, annex F. Mirror contacts are required in feedback circuits of safety controls. The mirror contact function informs about the switching state and ensures that the NC contact of the auxiliary contact is not closed at the same time as the NO main contact.
The compact switching device can be integrated especially in areas where there is no space for larger series. Since the C800 series can reliably switch in both directions of current, it is ideally suited for applications with energy recovery. In battery-powered and hybrid vehicles, the units can be used as main contactors directly in the Battery Disconnect Unit (BDU). Here, C800 series contactors reliably ensure the galvanic isolation of both poles of the battery from the vehicle’s powertrain in the event of a fault.
Type of voltage | DC bi-directional |
Main contacts, configuration | 1 NO |
Rated operating voltage Ue | 1,000 V |
Rated insulation voltage Ui | 1,000 V |
Rated impulse withstand voltage Uimp | 2.5 kV |
Pollution degree | PD3 |
Conv. thermal current Ith | 500 A @ 8 h Cross-section 185 mm2 Terminal temperature max. 185° C Ambient temperature max. 80° C |
Rated short-time withstand current Icw | 6,000 A @ t = 20 ms < 25,000 A @ t < 20 ms (contact welding, no explosion, no fire) |
Rated short-circuit making capacity Icm | 4,500 A @ L < 50 µH |
Aux. contact | 1 NC (Ui = 24 V, Ith = 2 A) |
Coil | 12 V DC Pull in (1 sec max.)/Hold: 11.6 V DC/3.8 V DC, 3.2 A DC/1.1 A DC 24 V DC Pull in (1 sec max.)/Hold: 15.8 V DC/5.2 V DC, 2.4 A DC/0.8 A DC PWM control: external Coil suppression: external |
Vibration | LV 124, M04: Profile D ISO 16750-3: Profile IV |
Shock | LV 124, M05: 50g ISO 16750-3: 6 ms (Temporary contact closing @ > 20 g / 6 ms) |
Mounting orientation | horizontal, vertical |
Temperature range | –40° C ... +95° C |
Mechanical endurance | 200,000 operations |