The R8845U1003 from Honeywell is a Universal Switching Relay with internal transformer. This switching relay provides intermediate switching of line voltage and low voltage devices from a line voltage or low voltage controller. It is typically applied in Hydronic heating systems.
Honeywell Universal Switching Relays R8845U with 24 V transformer provide intermediate switching of line-and low-voltage devices from a line- or low-voltage controller and is typically applied in Hydronic heating systems.

Features:

• Replaceable socketed relays;
• Two troubleshooting LED;
• Push-to-test button;
• Replaceable transformer fuse;
• Low-voltage contact rating for Powerpile applications;
• Long-life DC relay drive control technology;
• Relay for use with external 24 Vac or 24 Vdc supply, with line-voltage control, or with internal 24 V transformer supply;
• One model replaces many competitor models;
• One model may replace many Honeywell models:R182A,B,C,J; R482A,B,C,J; R845; R882A,B,C,J and RA832;
• Includes integral transformer, enclosure;
• Approvals of Canadian Underwriters Laboratories and Underwriters Laboratories Inc.

Technical Specifications:

• Switching Action: Two SPST, plus PowerPile® rated low voltage SPST relay. (If normally closed contacts are needed, use RA889A);
• Coil Ratings Current: 0.4A;
• Coil Ratings Voltage: 24 Vac;
• Thermostat Heat Anticipator Setting: 0.12A;
• Transformer Primary Rating: 120V, 60 Hz;
• Transformer Secondary Rating: 24V, 12 VA max., 9 VA available for external load. Secondary protected by replaceable 1A automotive fuse;
• Temperature Range: (Ambient) -20 F to +120 F;
• Thermostat Compatibility: Honeywell electromechanical and electronic 2- or 3-wire;
• Dimensions: 6-1/4" high x 4-7/16" wide x 3-1/2" deep;
• Electrical Connections (Control Circuit): 2 or 3-wire;
• Electrical Ratings (Primary Voltage): 120V, 60 Hz;
• Contacts Electrical Ratings (120 Vac AFL): 7.4A AFL, 44.4A ALR on each set of line-voltage contacts. •Maximum connected load is 2000 VA;
• Replacement Parts: 32002190-001 Circulator Replacement Relay;
• Operating Humidity Range (% RH): 0 to 90% RH, non-condensing;