4A circuit breaker for a refrigerator?
Commonwealth countries normally use British standards in electrical wiring. For household wiring, there will be two distinct outlet from the distribution/circuit breaker board. One is 6A lines for the lighting circuits, and another one is 20A lines for all power outlet sockets. Lighting circuits are wired using 1.25 millimeter squared wires and the power outlet wires are 2.5 millimeter squared copper cross section area.

So, what you might have read from the internet is, anything connected or plugged in to the outlet socket is protected by the 20amp breakers. These breakers are rated actually to protect the wires in the house wiring, not to protect the appliances plugged to the sockets. 

Properly rated fuse is already attached in your appliance power plug or embedded in its internal wiring. The 200Watts chiller is definitely consumes less than one ampere nominal current and its startup current may be three times higher, no way a 20Amps breaker will protect it unless it fully burnt and melt down.