Adjustable Electric water heater controller

The EAT500 series controls are designed to meet the high electrical capacity requirements of electric water heaters. Both use a temperature sensitive bimetal disc to deliver snap-action to the contacts. The speed and force of contact separation provides long-dependable control life at high electrical loads.

Switch Actions

The EAT500 is available in two switch actions: Automatic reset SPST – The switch opens the normally closed contacts on temperature rise. The contacts automatically return to the closed position when temperatures return to the reset point. Automatic reset SPDT – This operation is the same as the SPST with the addition of an auxiliary set of contacts, which make circuit upon opening of the normally closed contacts and breaks this circuit upon automatic reset.

Specification

Supply Voltage : 90VAC ~ 260VAC
Power consumption : 0.6 VA
Internal sensor: NTC
Control: ON/OFF control
Setting : Analog setting
Control output : Relay output –SPNO, 40A 240VAC
Storage temperature : -10~80℃
Operating temperature : -10~75℃

Temperature accuracy : ± 2℃
On-off differential : customize
Insulation resistance : DC500V/100MΩ,AC1200/10mA/1sec.
Weight : 78 g
Terminal recommend tightening torque : 15kgf-cm
Size : 87.6mm x 47mm x 27.2mm
Life expectancy(Relay): 30000 times (frequency: 900 times/hr)

• Zero-Arc algorithm extends Relay's life cycle
• 10–32 tin plated terminal screws for electrical connections
• Single pole, single throw or single pole, double throw, open on temperature rise construction
• Welded construction used on all internal current carrying components for greater electrical integrity

Typical Application

The thermostats and wiring diagram (shown on next page) are typical of a residential electrical storage water heater installation using two heating elements for non-simultaneous operation. The upper electrical control is a combination EAT500 SPDT regulating thermostat and a AT500PM DPST manual reset limiting thermostat. The lower electrical control is a EAT500 SPST electric thermostat. All the thermostats sense the surface temperature of the water heater tank. The AT500PM function is to provide full power disconnect (through both power conductors) in the event of an overheat condition. The EAT500 SPDT normally closed contacts route power to the upper heating element. When the EAT500 SPDT control reaches its set temperature, its switch action breaks power to the upper heating element and switches power to the lower heating element through the normally closed contacts of the EAT500 SPST. When its set point is satisfied, the switch action breaks power to the lower heating element.