Date: 201812
Local time of day: 0601-1200
Location: ZZZ.TRACON, US
Light: Daylight
Aircraft: B737-800
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise; Descent
Airspace: Class B ZZZ
ATC / advisory: TRACON ZZZ
Aircraft component: Electrical Distribution
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Human factors: Situational Awareness
Second reporter function: Pilot Flying; First Officer
Anomaly: Aircraft Equipment Problem Less Severe; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Detector: Person Flight Attendant
When detected: In-flight
Result: Flight Crew Landed in Emergency Condition
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: During cruise the flight attendants in the aft galley called to let me know that all five of the aft galley circuit breakers had popped. They asked if they should reset them; and I told them definitely not to. We checked the cockpit circuit breakers; which were all normal. I sent an ACARS message to Dispatch to let them know about the circuit breakers and asked them to pass it along to Maintenance Control. Just prior to descent; we smelled a strong sulfury odor in the cockpit that dissipated after about a minute. We had the same odor a few minutes later. At this point; we thought that it was someone in the lavatory. The flight attendants called us to let us know that they also smelled it; but that there was no one in the lavatory. The smell was gone again shortly; so I told them to keep us informed. By the third time that we had the smell; I asked them to see if someone could have a colostomy bag or if there was an obvious source that could be the cause. They said that the passengers in the front rows of the airplane all thought that someone had bad gas. They checked and said that there was no bag. I asked; but at this point it did not smell like any type of a fire to them. I asked them to try to isolate the location of the smell and to check for smoke. At this point we were about twenty minutes from landing. At about 12;000 feet on the arrival; the flight attendants called to tell me that the odor was strongest at about row 10; there was no obvious smoke; and the passengers in the forward cabin all had their noses covered. They said that they now smelled an electrical burning smell at row 10. I asked if they all agreed with this; and they all did believe it was electrical. I had transferred control of the airplane to the First Officer to fly the arrival and approach as we were now descending through about 8000 feet. We let Approach Control know that we were [requesting priority] and would like to have emergency personnel standing by at the runway to check for any obvious smoke. We were immediately cleared for the approach and cleared to land. I ran the 'Smoke; Fire or Fumes' checklist as we configured for the approach. After we finished the checklist; I quickly informed the flight attendants of what would happen once we landed. We landed and cleared the runway to hold on [the] intersection. I informed the passengers that we were going to have a fire truck inspect the aircraft due to the odor on the airplane out of an abundance of caution. Fire Personnel did an inspection of the aircraft and saw no smoke or hot spots on the aircraft. At this point; we had no odors in the aircraft and had not since we had run the QRH checklist. We asked them to follow us to the gate so that we could deplane the passengers and have them inspect the interior of the aircraft. I made another PA to the passengers to let them know that everything was fine and safe; and that they would see the fire trucks as they followed us to the gate.At the gate; I quickly spoke with Dispatch to let her know what was going on and that I would call back once we had deplaned and inspected the airplane. We deplaned the passengers as I spoke with the Fire Personnel in the jetway; and they said that they still saw no hot spots on the aircraft but would inspect the cabin. At this point; our A Flight Attendant let me know that both of the forward galley circuit breakers had popped at some point and that all of the water had drained out of the potable water tank. The passengers all seemed happy and no one seemed concerned. We saw no evidence of a fire in the airplane and there was no remaining odor. I spoke with my Crew to make sure that they were okay to continue on our next flight and then had a conference call with Dispatch and a Chief Pilot. I also spoke with Maintenance Control to explain what had happened. The aircraft was taken out of service; and I made a logbook entry and stayed with Maintenance until he let me know that Company was sending Mechanics.


Second narrative: [Report narrative contained no additional information.]


Synopsis: B737-800 flight crew reported sulfur and burning electrical odors in the cabin.