Heelo
I have similar issues since Sierra installed on a iMac 27" i7 late 2013
I do not if it will of any help but this is the log entries.
016-10-03 18:10:20.914219+0200 localhost kernel[0]: (AppleACPIPlatform) ACPI SLEEP
2016-10-03 19:49:49.999372+0200 localhost kernel[0]: (AppleSMC) Previous sleep cause: 5
2016-10-03 19:49:50.685725+0200 localhost apsd[103]: (CoreDaemon) <APSTCPStream: 0x7ff5f45201a0>: Configuring request for sleep proxy keep alives for environment production
2016-10-03 19:49:51.397710+0200 localhost kernel[0]: (AirPortBrcm4360) ARPT: 158544.724397: IOPMPowerSource Information: onWake, SleepType: Normal Sleep,
2016-10-03 19:49:51.411907+0200 localhost kernel[0]: PMRD: prevent idle sleep list: IODisplayWrangler+ (1)
2016-10-03 19:49:51.411909+0200 localhost kernel[0]: prevent idle sleep list: IODisplayWrangler+ (1)
2016-10-03 19:49:59.872429+0200 localhost apsd[103]: (CoreDaemon) <APSTCPStream: 0x7ff5f4416360>: Configuring request for sleep proxy keep alives for environment production
2016-10-03 19:50:03.939227+0200 localhost apsd[103]: (CoreDaemon) <APSTCPStream: 0x7ff5f441abf0>: Configuring request for sleep proxy keep alives for environment production
2016-10-03 19:50:06.464598+0200 localhost apsd[103]: (CoreDaemon) <APSTCPStream: 0x7ff5f6b18190>: Configuring request for sleep proxy keep alives for environment production
2016-10-03 19:55:30.462564+0200 localhost kernel[0]: (AppleACPIPlatform) ACPI: sleep states S3 S4 S5
2016-10-03 19:55:30.474989+0200 localhost kernel[0]: PMRD: Sleep failure code 0x00340530 0x03000032
2016-10-03 19:55:30.474990+0200 localhost kernel[0]: Sleep failure code 0x00340530 0x03000032
2016-10-03 19:55:30.999931+0200 localhost kernel[0]: PMRD: System was rebooted due to Sleep/Wake failure
2016-10-03 19:55:30.999932+0200 localhost kernel[0]: System was rebooted due to Sleep/Wake failure