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- Rated current
About rated current
The rated current of a connector is determined by the temperature rise caused by the current value when the connector is energized.
At our company, the rated current is the current value that increases by 30°C when all poles are energized. If the ambient temperature is 30°C lower than the rated temperature, current can flow up to the rated value.
On the other hand, if the number of poles to be loaded with high current is not all poles, or if the ambient temperature is lower than the rated temperature by 30°C, it may not be a problem to load a current value that exceeds the rating. Please contact us from our website or contact the sales representative in charge of your company.
Rated current of our products
Key to rated current
The key to rated current is temperature rise. Unless otherwise specified,
① When all poles are energized
② In windless environment
③ With standard board mounting
④ The temperature is within 30℃ from the time of specific energization
The current value that satisfies these conditions is defined as the "maximum rated current." In addition, it takes a certain amount of time for the connector to rise due to energization until the balance between heat generation and heat dissipation is achieved. When verifying reliability tests, etc., we perform these tests while ascertaining the behavior of temperature rises.
Connector temperature rise due to energization
Ambient temperature at which maximum rated current can be used
The rated temperature of the connector is the temperature at which the functions of the product can be maintained soundly under the applicable temperature for the continuous use time or long-term use time specified in various standards. Therefore, it is necessary to consider the rated temperature including "temperature rise due to energization/operation".
The temperature of the connector before energization, that is, the ambient temperature, must be lower than the rated temperature, and the difference is the allowable temperature rise due to energization. For example, if you want the full rated current to pass through the connector, the ambient temperature must be at least 30°C below the rated temperature.
Operating connector temperature and rated temperature
Actual allowable ampacity depending on rated temperature
Suppose we have two connectors with the same temperature rise characteristics, i.e. two connectors with the same maximum current rating. However, suppose one was rated at 105°C and the other at 125°C. What will happen if it is used in an environment with an ambient temperature of 95°C?
A 105°C rated connector only allows a temperature rise of 10°C, so it is not possible to carry current up to the maximum rated current. For example, even if the rating is 3.0A, you can only use 1.0A or less.
On the other hand, if it is rated at 125°C, it will have enough margin to reach the maximum temperature rise, so it can flow exactly up to the maximum rated temperature of 3.0A. Thus, a connector with a higher temperature rating can carry more current than one with a lower rating in the same ambient temperature environment.
When there is a difference in rated temperature
A case where a current value higher than the maximum rated current can flow under a specific usage environment
Since it is not possible to make assumptions at the time of product specification at our company, we cannot specify or recommend it as a specification item, but in the following cases, there is a possibility that a current exceeding the maximum rating can flow.
① When a large current flows only to a specific pin
(2) When the heat dissipation of the connector part is strengthened by forced airflow, etc.
(3) When there is a measure to reduce the temperature rise due to the specifications of the heat dissipation board, etc.
④ When the ambient temperature is guaranteed to be much lower than the rated temperature of -30°C
⑤ rush current Momentary over rating due to
However, in both cases, verification based on the details is required. Ultimately, the decision will be made based on the specifications of the customer's device, but when considering it, we can cooperate with evaluation and verification according to the content, so please disclose the actual specifications and consult us.