Name: Resideo R8845U1003/U Multisystem Switching Relay with Internal Transformer
Brand: Resideo
SKU: HONE-R8845U1003/U
Price: 103.26 USD
Availability: InStock

Multisystem Switching Relay with Internal Transformer

Roll over image to zoom in Click on image to zoom

Frequency	60 Hz
Electrical Connections	Control Circuit- 2 or 3-wire
Operating Humidity	0 to 90% RH, non-condensing
Application	Enclosed Universal switching relay with internal transformer for 24 volt 2 or 3 wire thermostat control of line voltage devices. Two line voltage SPST relays and one low voltage SPST relay with PowerPile® rating.
Includes	Integral transformer, enclosure
Dimensions	6 1/4 in. high x 4 7/16 in. wide x 3 1/2 in. deep
UL	Listed: File No. E4436, Guide No. XAPX
Temperature Ratings (F)	Ambient: -20 F to +120 F
Approvals, Canadian Underwriters Laboratories Inc.	Listed: Guide No. XAPX7.
Switching	Two SPST, plus PowerPile® rated low voltage SPST relay. (If normally closed contacts are needed, use RA889A).
Contact Ratings (AFL)	7.4A AFL, 44.4A @ 120 Vac on each set of line-voltage contacts
Input Voltage	120V
Coil Ratings Voltage	24 Vac
Coil Ratings Current	0.4A
Electrical Ratings, Contacts	Maximum connected load is 2000 VA
Transformer	Secondary Rating-24 Vac, 12 VA max., 9 VA available for external load. Secondary protected by replaceable 1A automotive fuse.

The R8845U1003 is a switching relay from Resideo (Honeywell Home).

A relay lets a small control signal switch a much larger load. The thermostat or control board energizes a coil; the coil pulls contacts closed; the contacts carry the current that runs a blower, a circulator or an electric heat element. Nothing on the thermostat side ever sees line voltage.

This relay carries an internal transformer, so it makes its own 24 V control power instead of borrowing it from the system. On a retrofit that is often the deciding feature: adding a relay to a circuit that is already at the limit of its transformer causes exactly the intermittent faults that are hardest to chase.

Match the coil voltage and the contact rating to what you are replacing. A relay with the right coil but an undersized contact will work on the bench and weld shut in service.

Brand: Resideo (Honeywell Home)
Manufacturer Part #: R8845U1003/U
Type: Switching relay
Internal transformer: Yes
Shipping weight: 1.9 lb
Category: Relays

Full Specifications

Application	Universal switching relay for 24 volt 2 or 3 wire thermostat control of line voltage devices
Product Features	Replaceable socketed relays, Two troubleshooting LED, Low voltage contact rating for PowerPile® applications, Replaceable transformer fuse, Relay for use with external 24 Vac or 24 Vdc supply, with line
Approvals and Standards	UL Listed: File No. E4436, Guide No. XAPX, CSA Listed: Guide No. XAPX7
Includes	Integral transformer, Enclosure
Coil Rating Voltage	24 V ac
Coil Connection Type	Control Circuit 2 or 3 Wire
Number of Poles	1 Pole
Power Supply Frequency	60 Hz
Switch Action	Two SPST
Compatible Thermostat	Low voltage (Class 2) 2-wire Thermostat
Warranty	1 Year
Product Height	6.25 in, 159 mm
Product Length	3.5 in, 89 mm
Product Width	4.44 in, 118 mm