Every default plan has 3000 API calls per entity per hour.
The rate starts counting after the first request has been made. The rate limit will reset back to your original amount when an hour has passed. When your API calls are depleted, until the hour is finished, you will not be able to request data from the entity for which you surpassed the rate limit . You can however make requests to other entities that have not hit the rate-limit.
For example: If you make the first of your requests at 18:18 UTC it will be reset at 19:18.
When you make a request, the API response includes a rate_limit object in the response, this object has 3 properties: