The Goodman-Amana Heat Sequencer 5KW, B1256558, is a crucial OEM replacement part for electric furnace heat strips, designed to precisely control the timing of turning on/off heating elements and the blower motor in stages for efficient, safe, and consistent heating in Goodman, Amana, and Janitrol HVAC systems, often replacing older models like B1256551. B1256558 controls staged heating, it is controlling by managing the sequence, ensuring heating elements activate in the correct order and at specific temperature/time intervals (e.g., 10-20 seconds on, 30-70 seconds off). It manages the blower motor and also coordinates the blower motor's operation with the heating elements.

Key specifications:

• Part Number: B1256558 (also replaces B1256551).
• Power: Rated for 5kW (5,000 watts) electric heat systems.
• Type: A single-pole, time-delay relay (often 24V). 
• Amperage Rating: 30 A (Amps).
• Control Circuit (Coil): 24 VAC.
• Stage: It is a 1-stage heat sequencer relay.
• Product Class - (PIM)Heat Kits
• Dimensions - (Unit Depth): 1.626 in
• Dimensions - (Unit Width): 2-9/16 in
• Dimensions - (Unit Height): 1.5 in
• Weight - (Unit: 2 lb
• Wattage (Power Handling): The component is used for applications up to 5 kW (kilowatts) of electric heat.
  
• Main Power Circuit (Switches): Capable of handling line voltage, typically 120 VAC, 240 VAC, or 480 VAC, depending on the specific heater kit configuration it's installed in.
• Timing:
  "On" (Activation) Time Delay: 25–50 seconds.
  "Off" (Deactivation/Cool-down) Time Delay: 40–110 seconds.

The B1256558 part number is affiliated with and can be cross-referenced with the following numbers:

• B12565-58: A common representation of the part number found on the physical component.
• B1256551: An older, obsolete manufacturer part number that the B1256558 replaces.
• BT1256500: Another obsolete or alternative stock number used by manufacturers and suppliers.
• 309561: A stock or part number used by some distributors.
• 309837: Another part number sometimes associated with Therm-o-disc versions of the switch.
• L39-276: A catalog number used by some wholesale suppliers.
• Q109: A universal/generic part number from manufacturers like Supco that can replace the B1256558, provided the specifications match. 

For specific timing specifications, the original sequencer had on/off delays rated at H10-20 (Heat On: 10-20 seconds) and C30-70 (Cool Off: 30-70 seconds). The generic replacement will typically have a 24 VAC control circuit and a time delay of 25-50 seconds to turn on and 40-110 seconds to turn off.

Here are some specific model numbers compatible with the B1256558 heat sequencer:

A Series Air Handlers:

• A18-05C, A18-08, A18-10
• A24-05, A24-05C, A24-08, A24-08C, A24-10, A24-10C
• A30-05, A30-08, A30-08C, A30-10, A30-10C, A30-15
• A32-03, A32-05, A32-05C, A32-08, A32-08C, A32-10, A32-15
• A36-05, A36-05C, A36-06, A36-08, A36-08C, A36-10, A36-10C, A36-15, A36-20
• A42-08C, A42-10, A42-10C, A42-15, A42-20

AWB Series:

• AWB18-05C, AWB18-05D
• AWB30-05CB, AWB30-05CC, AWB30-05CD, AWB30-05CE

AWUF and ACNF Series:

• AWUF24051AA, AWUF240516AA
• ACNF240516AA, ACNF240516AB, ACNF30051BA