Whenever equipment or circuits are not working, always start by confirming that there is voltage available. If there is voltage at the source of supply, then you have confirmed that the problem is downstream from that point.
If the main overcurrent protection is provided by a circuit breaker, check that the handle is in the “On” position, and not the “Off” or “Tripped” position. A circuit breaker indicates that it has tripped when the handle is in the centre position. To reset, push the handle fully off, then on. If the handle “trips” again suddenly, then there is likely a short circuit somewhere bypassing a load.
If the main overcurrent protection is provided by a fusible disconnect, the status of the fuses will determine if voltage is present. There are two tests that can confirm if a fuse link is intact: an ohmmeter continuity test and the crisscross voltmeter method.
Reference
Basic Motor Control by Aaron Lee and Chad Flinn is used under a CC BY 4.0 Licence.