Lack of preventive maintenance can be very costly. The majority of malfunctions are a result of improper case. Hoever, if you take the time to inspect your control panels, you will find that they have long term liability.. Complete panel solution..
Stage 1...
Stage 2... Only if stage 1 had fault,
the indicating strip will meassure fault, for detail , please request at engineertfl@gmail.com , wechat 36461720