It might be a Metal Oxide Varistor (MOV) rated for 270V. The A3 may be an energy rating (joules).
These are often used across AC power lines in circuits like power supplies, to clip off any voltage spikes that come in. In your case, it would clip anything around 270V or higher.
These can blow if there is a large surge on the powerline, one bigger than the MOV can handle.
Across a small electric motor, it could be a very small capacitance capacitor, 27pF. Unusual for such a small value to be across a motor...
Someone else may come up with an exact match and post....