Abstract: A climate control system or a data center includes a computer room air conditioner (CRAC) and an air economizer. A control module determines whether outside air is suitable for use in cooling the data. If the outside air is suitable for use, outside air and not the CRAC is used to cool the data center when the dry bulb temperature of the outside air is below a minimum set point. The outside air is conditioned before it is introduced as supply air so that it is above a minimum temperature. If the outside air is suitable for use and the dry bulb temperature of the outside air is above the set point, the control module determines a cooling percentage of cooling of the data center to be provided by the CRAC and a cooling percentage to be provided by the outside air.

Abstract: A data center has equipment racks in which electronic equipment is disposed and a climate control system that includes a computer room air conditioner (CRAC) and an air economizer. The climate control system includes a control module that controls the climate control system. The control module determines whether outside air is suitable for use in cooling the data center based on the dry bulb temperature and humidity of the outside air. If the outside air is not suitable for, only the CRAC is used to cool the data center. If the outside air is suitable for use, outside air and not the CRAC is used to cool the data center when the dry bulb temperature of the outside air is below a minimum outside air dry bulb temperature set point. The outside air is conditioned before it is introduced as supply air into the data center so that the supply air is above a minimum temperature.

Abstract: The present invention provides an electrical circuit that measures the ground current due to insulation leakage in electrical heating elements. The circuit uses a CT to measure the current being supplied to at least one of a plurality of electrical heating elements. Using a comparator circuit and noise rejection circuitry to prevent erroneous tripping, once the current reaches a predetermined threshold, a signal is sent to a switch that causes a non-volatile memory device to clear thereby de-energizing the coil of the contactor that provides power to at least one of the heating elements.

Abstract: The present invention provides an electrical circuit that measures the ground current due to insulation leakage in electrical heating elements. The circuit uses a CT to measure the current being supplied to at least one of a plurality of electrical heating elements. Using a comparator circuit and noise rejection circuitry to prevent erroneous tripping, once the current reaches a predetermined threshold, a signal is sent to a switch that causes a non-volatile memory device to clear thereby de-energizing the coil of the contactor that provides power to at least one of the heating elements.