Principle Of Operation - Omron S8VS - MODEL 15-30-60-90-120-180-240W Manual

■ Maintenance Forecast Monitor Function
The Power Supply is equipped with electrolytic capacitors.
The electrolyte inside the electrolytic capacitor penetrates the seal-
ing rubber and evaporates as time passes since it is manufactured,
which causes deterioration of characteristics such as decreasing the
capacitance, etc.
Due to this deterioration of the characteristics of the electrolytic
capacitor, the Power Supply decreases its performance as time
passes.
Relationship between Indicated Values and Output of Set Values
Initial capacity
Capacity level
at replacement
Capacity of Capacitor
Note: This function can be set only on the S8VS-
09024A@, S8VS-12024A@, S8VS-18024A@,
and S8VS-24024A@.

■ Principle of Operation

The deterioration speed of the electrolytic capacitor varies consider-
ably according to the ambient temperature. (Generally the speed fol-
lows "Rule of Two for every 10°C"; for every 10°C increase in
temperature the rate of degradation doubles according to Arrhenius's
equation.) The S8VS-@@@24A@ monitors the temperature inside
the power supply, and calculates the amount of deterioration accord-
ing to the running hours and inside temperature. Judging by this
amount of deterioration, the power supply will give the alarm indica-
tion and output when the period left for maintenance reaches the set
value.
Note: 1. Due to degradation of internal electronic parts, replace the
power supply approximately 15 years after purchase even if
indication and output of maintenance forecast monitor are
not issued.
2. The maintenance forecast is accelerated or decelerated ac-
cording to operating conditions. Periodically check indica-
tion.
3. Acceleration or deceleration of the maintenance forecast
may cause the output to repeatedly go ON/OFF.
Only the S8VS-09024A@, S8VS-12024A@, S8VS-
18024A@, and S8VS-24024A@ are equipped with output.
4. The accuracy of the maintenance forecast function may be
adversely affected by applications in which the AC input is
frequently turned ON/OFF.
L: Maintenance forecast set value (See note.)
0.0 to 5.0, 0.5 steps
Main display
Maintenance forecast monitor output
The maintenance forecast monitor function shows an approximate
period left for maintenance of the Power Supply due to deterioration
of electrolytic capacitors. When the period left for maintenance that
the power supply forecasts reaches the set value, an alarm is indi-
cated and an output signal is triggered.
Use this function to know the approximate replacement timing of the
Power Supply.
Note: The maintenance forecast monitor function indicates an ap-
proximate period left for maintenance, based on deterioration
of the electrolytic capacitor. It does not predict failures caused
by other reasons.
In case of setting L between 2.5 and 5 years.
(L−0.5)
5.0
L=2.5
L=0.5
The numerical value
decreases with time.
■ Reference Values
Reliability Value
(MTBF)
Standard types
60 W:
90 W:
120 W:
180 W:
240 W:
Definition MTBF stands for Mean Time Between Failures, which is
calculated according to the probability of accidental de-
vice failures, and indicates reliability of devices.
Therefore, it does not necessarily represent a life of the
product.
Life 10 yrs. min.
expectancy
Definition The life expectancy indicates average operating hours
under the ambient temperature of 40°C and a load rate
of 50%. Normally this is determined by the life expect-
ancy of the built-in aluminum electrolytic capacitor.
Note: The maintenance forecast is the service life (the power supply's
internal temperature is monitored at all times) of the internal
electrolytic capacitor in actual operating conditions, and varies
according to the customer's operating conditions. 15 years is
taken as the maximum period of the maintenance forecast.
Switch Mode Power Supply
"1.0" is displayed on the main display for the
duration that the maintenance forecast up to
replacement satisfies the condition 1.0 ≤ T < 1.5.
2.5 2.0 1.5 1.0 0.5
• With Maintenance Forecast
Monitor types
• With Total Run Time Monitor types
400,000 hrs,
390,000 hrs,
280,000 hrs,
260,000 hrs,
220,000 hrs,
0
T: Maintenance time
until replacement
230,000 hrs,
200,000 hrs,
190,000 hrs,
180,000 hrs,
160,000 hrs,
S8VS
15