| 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. |
Description
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