| Hercules Product Info | |
|---|---|
| Hercules Product Id | 21M51U-843 |
| Product Description | UNIVERSAL 2 STAGE CONT BOARD |
| Unit of Measure | EA |
| Manufacturer Info | |
|---|---|
| Manufacturer Name | Emerson Electric |
| Brand Name | White-Rodgers |
| Part Number | 21M51U-843 |
| Product UPC | 786710540707 |
| Product Description | White-Rodgers 21M51U-843 Universal Hot Surface Ignition Control, 25 VAC, 530 mA |
| Product Features |
|---|
| Includes: 21D64-2 Silicon Nitride Igniter Upgrade Kit |
| 120 VAC 3 speed PSC circulator output, two-speed inducer output, two stage gas valve output |
| Pushbutton fault history retrieval |
| Furnace status LED - tri-color (green, red and amber) |
| Heat fan off delay (dipswitch selectable), fan on delay for cooling |
| Auto second stage delay (dipswitch selectable) |
| -40 to 175 deg F |
| 2-stage gas valve output |
| 3 A fuse protection |
| Pressure switch inputs and monitoring |
| Flash microprocessor with non-volatile memory |
| Flame current measurement points |
| 1.5 A valve relay |
| 2.2 FLA to 3.5 LRA inducer relay |
| 14.5 FLA to 25 LRA circulator relay |
| 1 a max at 120 VAC humidity |
| 1 a max at 120 VAC electronic air cleaning |
| 4 a max at 132 VAC ignitor relay |
| 0.3 uA DC max current for flame detection |
| 0.1 uA DC min current for flame detection |
| 100 M ohm leakage resistance, 3 speed PSC blower motor systems |
| Product Documents | |
|---|---|
| Document Type | Download Link |
| Catalog | 21M51U-843_Catalog (pdf) |
| Specification Sheet | 21M51U-843_Specification Sheet (pdf) |
| Product Specifications | |
|---|---|
| Accessory Type | Hot Surface Ignition Control |
| Amperage Rating | 530 mA |
| Depth | 1-1/4 mA |
| Domestic/Import | Import |
| Electrical Connections | 1/4 in Spade Terminal and Molex Plug |
| Gas Type | Liquid Propane/Natural Gas |
| Height | 8 in |
| Igniter Warm-Up Time | 17 s |
| Lead Length | 15-1/2 in |
| Probe Length | 15-1/2 in |
| Type | Universal |
| Voltage Rating | 25 VAC |
| Width | 5-1/4 in |
| Certifications | CSA Certified |
| Country of Origin | MX |