Model: NL-YZKQ-6

The problem

A liquid-expansion thermostat for an electric water heater must switch its sensing bulb through hundreds of thousands of hot cycles. Manual hot-bath swapping covers only a few hundred cycles a day, and lagging bulb response or welded contacts surface as user complaints after installation. With several units running in parallel nobody remembers which one failed at which cycle count, and one bad sample can void a whole batch of data.

Capability

Six stations run in parallel, each counting its own 1-999999 cycles independently. The oven heats from ambient to 150C for thermostats of 2-5.5kW water heaters; heating and dwell times run 0-999s and cooling 0-999s, with compressed air at 0.4-0.6MPa blowing multi-jet onto the bulb for rapid reset, so the cycle rate reaches at least one action per 300 seconds, day and night. Each station has an indicator lamp watching thermostat state; when a unit fails within the fault-tolerance count the system raises an audible and visual alarm and stops only that channel, leaving the other five running. When the preset count is reached the test stops automatically and the screen shows the completion message. Contact assessment uses a 0-40A adjustable load cabinet on two independent channels so thermostats switch real current. A PLC plus PC interface sets the test mode, heating and cooling times, contact states, preset, current, pass and fail counts and station engagement, with live status and full history. The frame is aluminium profile with painted A3 panels; a manual cable reel is included and a third-party calibration certificate ships with the machine.

Key specifications

• Application: endurance of liquid-expansion thermostats for electric water heaters
• Stations: 6, independently engaged, independently counted
• Counting range: 1-999999 cycles per station
• Heating: oven from ambient to 150C settable
• Samples: liquid-expansion thermostats of 2-5.5kW water heaters
• Heating time: 0-999s settable
• Cooling: compressed air at 0.4-0.6MPa, rapid multi-jet cooling
• Cooling time: 0-999s settable
• Cycle rate: at least one action per 300 seconds, fully automatic
• Monitoring: per-station indicator lamps, fault-tolerance alarm stops only that channel
• Load cabinet: 0-40A adjustable on 2 independent channels, forced-air cooled
• Control: PLC + PC, on-screen parameters, live history access

Applications

Outgoing life inspection at thermostat plants; incoming reliability verification at water-heater makers; development screening and type testing of thermostats; commissioned life testing at third-party laboratories

About the manufacturer

Guangdong Endurance Electronic Equipment Co., Ltd provides non-standard customization, drawing confirmation, factory acceptance, on-site installation and commissioning, operation training and long-term technical service; 12-month warranty and long-term spare parts supply. Tel: 0760-88500902 / 13416787649. Web: en.zsnaili.com.