B737 MAX 8
Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 150; Flight Crew Type 150
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Provided Assistance; Flight Crew Landed As Precaution; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Returned To Departure Airport; General Flight Cancelled / Delayed; General Maintenance Action
Aircraft
The A Flight Attendant notified the First Officer that they had lost power in all four galleys. At Top of Climb; we SAT COMM'd Dispatch; Maintenance and the Chief Pilot. We determined the galley breakers were in the EE Bay and unable to determine status. No QRH procedure was applicable. We thought we might have a load shedding issue. After a discussion about the possible issues; causes and potential outcomes; we decided we would make a precautionary divert back to ZZZ. We were still in radio range of Center. We got an initial heading then direct to ZZZZZ. We ran the Divert Checklist; considered our overweight landing brake cooling issues. We advise ATC and requested the fire trucks for a potential electrical and/or brake fire. The Captain landed on the longest runway at ZZZ ([Runway] XXL). The entire flight and landing were uneventful except as otherwise described.  Maintenance found no circuit breakers popped in the EE bay. They cycled the overhead panel CAB/UTIL switch at the gate and were able to restore power to all galleys.
At the top of climb the A-Flight Attendant called to let us know that all four galleys; power was out. The power was working on the ground and in the climb for a while. I checked the switch and it was on; ran the QRH (there was none) and checked the circuit breakers (none popped). I called Dispatch on the SAT and told him what was going on. He patched me in to Maintenance Control. In the meantime; the First Officer found the circuit breakers are in the EE Bay. Maintenance Control said the transfer bus could be load shedding. Dispatcher asked what I wanted to do.I said I wanted to talk to the Chief Pilot on Call. I discussed my concerns with the Chief Pilot; that the aircraft could be load shedding. I didn't feel like it was a good idea to continue. I called ATC and said we wanted to go back to ZZZ. We began the turn and we programmed the FMC for new destination. I called back to the FA's and told them why I felt it was a good idea to go back to ZZZ. Everyone agreed. I made an announcement to the passengers why we were turning around.Later I made a decision to request priority handling as a precaution due to the nature of the electrical system. I spoke to the FAs and told them why I did that. We discussed procedures on the ground; and explained to them it was highly unlikely any problems would occur; and not to get able bodied people; and no evacuation was necessary. I told them we would be landing in 19 minutes. I transferred the controls to myself for the overweight landing. First Officer told ATC we were advising and wanted CFR after landing; in case of any issues for hot brakes. Landing was soft and uneventful. First Officer ran brake cooling and found we could taxi to the gate. I told Tower we didn't need CFR anymore. I made an announcement to the passengers why CFR was there. Then we taxied to the gate uneventfully.
B737 MAX 8 flight crew reported loss of electrical power to all four galleys and elected to perform an air turn back and precautionary landing.