2. INSTALLATION 
2 -  5 
 
2.5 Parts having service lives 
Service lives of the following parts are listed below. However, the service life vary depending or operating 
methods and environment. If any fault is found in the parts, they must be replaced immediately regardless of 
their service lives. For parts replacement, please contact your sales representative. 
 
Part name  Life guideline 
Smoothing capacitor  10 years 
Relay 
Number of power-on and forced stop by EM1 
(Forced stop 1) times: 100,000 times 
Number of on and off for STO: 1,000,000 times 
Cooling fan  10,000 hours to 30,000 hours (2 years to 3 years) 
Absolute position battery  Refer to section 12.2. 
 
(1) Smoothing capacitor 
The characteristic of smoothing capacitor is deteriorated due to ripple currents, etc. The life of the 
capacitor greatly depends on ambient temperature and operating conditions. The capacitor will reach 
the end of its life in 10 years of continuous operation in normal air-conditioned environment (40 °C 
surrounding air temperature or less). 
 
(2) Relays 
Contact faults will occur due to contact wear arisen from switching currents. Relays reach the end of 
their lives when the power has been turned on and forced stop by EM1 (Forced stop 1) has occurred 
100,000 times in total, or when the STO has been turned on and off 1,000,000 times while the servo 
motor is stopped under servo-off state. However, the lives of relays may depend on the power supply 
capacity. 
 
(3)  Servo amplifier cooling fan 
The cooling fan bearings reach the end of their life in 10,000 hours to 30,000 hours. Normally, therefore, 
the cooling fan must be replaced in a few years of continuous operation as a guideline. It must also be 
changed if unusual noise or vibration is found during inspection. 
The life indicates under the yearly average ambient temperature of 40 °C, free from corrosive gas, 
flammable gas, oil mist, dust and dirt.