A Bimetal Thermostat Manufacturer Shaping the Future

Asahi Keiki Co., Ltd.

Current Capacity Based on Differences in Voltage and Load

These are conceptual reference values for microswitches, toggle switches, relays (1–10 A), and similar components.
Reference values based on a current capacity of 100% at 125 V AC. Reference values based on a current capacity of 100% for resistive loads.

Voltage Current
AC 125V 100%
AC 250V 70%
(Micro SW 60)
DC 24V 50%
DC 125V 5%
DC 24V [ Min. 50mA ]
Load Current
Resistive load
(COS φ = 1)
100%
Inductive load
(COS φ = 0.4)
50%
(Micro SW 60)
Motor Lamp 15%
(Micro SW 10)

Load inrush current

These are conceptual reference values based on a resistive load.

Load Inrush current
Incandescent lamp 10 to 15 times
0.3 to 0.4sec
Mercury vapor lamp 3 to 4 times
3 to 5 minutes
Fluorescent light 3 to 4 times
2 to 7sec
Motor 5 to 10 times
0.2 to 5sec
Solenoid 10 to 20 times
Approx. 0.1 sec
Solenoid relay 3 to 10 times
0.02 to 0.04sec

Electrical Ratings for Gold Crossbar Contact Item

Inductive load
Load AC rating DC rating
Resistive load AC 125V 0.5A
AC 50V 1A
DC 40V 0.5A
DC 24V 1A
[ Min. DC 5V 1mA ]
Inductive load AC 125V 0.2A
AC 24V 1A
DC 40V 0.2A
DC 10V 1A

When the circuit resistance specification after the end of life cycles is the same as the initial specification

Compatible Models

Thermostat time constant (thermal response speed)

The thermal response performance of a thermostat can be compared and evaluated using its time constant.

Time constant
When a sample is heated from room temperature to a certain temperature, there is a time delay before the target temperature is reached.
The time it takes for the temperature difference between room temperature and the target temperature to reach 63.2% of that difference is the time constant (thermal response rate).
Test Method
  1. How to Calculate the Time Constant Based on the Thermostat's Operating Time

    Place the thermostat on the hot plate and measure the time it takes to begin operating under constant pressure.
    After the measurement, calculate the thermal response time constant using the formula below.

    How to Calculate the Time Constant Based on the Thermostat's Operating Time How to Calculate the Time Constant Based on the Thermostat's Operating Time
  2. How to Measure Time Constants from a Test Implementation Chart (Temperature of a Bimetallic Disc)

    Thermal response test on a heating plate when the thermostat cover material was changed from 0.4 mm aluminum to 0.25 mm stainless steel
    Conditions: Aluminum heat plate temperature 150°C; no thermal grease used between the heat plate and the cover(This varies depending on the pressure, the shape and contact area of the cover, the material and shape of the bimetal, and whether grease is used.)

    Comparison of Response Characteristics Based on Cover Material on a Hot Plate: Temperature Tracking Characteristics Graph

    How to Measure Time Constants from a Test Implementation Chart (Temperature of a Bimetallic Disc)

    Click the image to view a larger version

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