Electrical devices must be installed in accordance with local building codes. To avoid any damage, switch off the main power at the consumer unit/fuse box. If you have any questions, contact a competent expert who is self-certified in electrical work. How to replace a blown fuse with a DIY home repair guide It's vital to use fuses with the proper rating; too low a rating may cause frequent blowing.
Electrical work requires extreme caution. Electrical devices must be installed in accordance with local building codes. Shut off the consumer unit or fuse box to avoid damage. Turn off the circuit breaker and secure it if feasible. Mark the device to show that you are working on it. If there are no hidden pipes or cables, secure the mounting box in place.