With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
chassisPs3Status
chassis Ps3 Status
1.3.6.1.4.1.9.5.1.2.21
not ok, the value of chassisPs3TestResult gives more detailed information about the power supply's failure condition(s). This object is only supported by systems that can have 3 or more power supplies.
Back to CISCO-STACK-MIB MIB page.
IPHost Network monitor allows you to monitor chassisPs3Status on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco mobile switches right now.