KNHE28 Water-to-Air
Panel-Mounted Heat Exchangers

This control consists of a temperature control thermostat and a solenoid valve. When the temperature within the enclosure drops below the thermostat set point due to decreased load or decreasing water temperature, the thermostat closes the solenoid valve. When the temperature increases to the set point (plus a differential) the thermostat opens the solenoid valve and the supply water cools the enclosure. In most models the Automatic Water Flow Control also includes a bypass flow meter which allows a small amount of water (0.25 gpm) to pass through the heat exchanger at all times.

Closes water-supply valve to prevent flooding if excess water accumulates in the drain pan. Signal circuit activates a user-supplied warning device. The low voltage power for the signal circuit is supplied by the user.

This protection increases reliability in hostile environments. This protection for the cooling system consists of an air cured coating applied to the brazed joints, providing a degree of protection from corrosive environments. This coating will withstand 1000 hours of salt spray per the ASTM B 117 test method. NOTE: Severe operational environments such as wastewater treatment and salt spray are likely to cause corrosion failure over a period of time regardless of coating. This coating provides protection to the external portion of the coil and does not protect from any corrosive elements in the cooling water used internally. Warranty: Corrosive conditions may affect the warranty coverage. Consult factory for warranty limitations in corrosive environments. NOTE: For additional corrosion protection options, contact factory.

Similar to the Airflow Switch shown in the Blower Accessories Section, the switch is installed in a suitable location in the air conditioner to detect loss of airflow, and sends a signal to a terminal block, through which user-installed wiring and warning devices are activated.

A thermostat is mounted inside the cabinet and attached to a sensor in the warm air return. When the air temperature increases to the set point, a signal is sent to a terminal block. User-installed wiring from the terminal block to local and/or remote warning devices (light, bell, siren, etc.) can be for normally open or closed operation.