IP slow fuses are designed for protection of DC electric distribution devices (up to 30 V) from current overload and short-circuit.
In case of the current overload, the heating element slowly heats up the copper base with soldered brackets. After the melting point of a low-melting solder is reached, the spring moves the brackets to the right and the circuit is broken.
In case of the short-circuit the heating element or the fuse blows out
Technical parameters
| Fuse type | Current capacity | Operation time | Operational conditions | |
| Temperature, oC | Air pressure | |||
| IP-5+75 | 1.25 1n | not less than 60 mins | +20; +60 | normal |
| -60 | 41 mmHg | |||
| 1.75 1n | not more than 30 mins | +20; +50 | normal | |
| 2.3 1n | not more than 30 mins | -60 | normal | |
| 6 1n | 1..20 s | +20 | normal | |
| IP-100-250 | 1n | not less than 60 mins | -60 | 41 mmHg |
| +50 | normal | |||
| 1.02 1n | not less than 30 mins | +50; +20 | normal | |
| 1.95 1n | not more than 30 mins | -60 | normal | |
| 2 1n | not more than 6 mins | +20 | normal | |
| 6 1n | not less than 0.5 s | +20; +50 | normal | |
