Procedure: Selecting Overload Heater Elements with Rockwell Automation Tools

 Procedure: Selecting Overload Heater Elements with Rockwell Automation Tools Purpose and scope

This procedure selects the correct thermal overload heater element for an Allen-Bradley NEMA starter using Rockwell Automation's online selection tools, so the overload trips at the right current for the motor it protects.

It applies to starters with Bulletin 592 eutectic-alloy (melting alloy) overload relays, such as Bulletin 509 full-voltage starters and related combination starters, which take W-series heater elements. It does not apply to solid-state overloads (such as the Bulletin 193/592 E1 Plus or E300), which are set by dial or software instead of by a replaceable heater.

Information to gather first

Collect these from the motor nameplate, the starter, and the site before opening the configurator. The heater choice depends on all of them.

Item	Where to find it	Why it matters
Motor full load current (FLC), A	Motor nameplate	The primary selection value; use nameplate FLC, not NEC table values
Service factor (SF)	Motor nameplate	SF below 1.15 means one heater size smaller
Marked temperature rise or insulation class	Motor nameplate	Rules assume SF ≥ 1.15 or rise ≤ 40 °C
Duty rating	Motor nameplate	Intermittent-duty motors need factory guidance
Starter bulletin, NEMA size, enclosure type	Starter nameplate or catalog number (e.g. 509-BOD)	Determines which selection table applies
Number of heaters (1Ø one element, or 3)	Overload relay	Single- and three-element relays use different tables
Trip class needed (10, 20, or 30)	Application / motor maker	Selects Type J, W, or WL element
Ambient temperature at starter and at motor, °C	Site survey	A difference over 10 °C requires a correction

For wye-delta (Bulletin 540) and part-winding (Bulletin 530) starters, note the starter type: the FLC is divided by 1.73 or 2.00 before selecting.

Procedure

Rockwell's online tools build the full starter catalog number, including the heater element, from your motor data. Screen labels change over time, so match the intent of each step rather than exact button names.

1. Open the tool. Go to rockwellautomation.com → Tools and choose Product Configurator ("Configure Now"). For a full motor-starter design with a BOM, Advisor (advisor.rockwellautomation.com) offers the same selection inside its power-control design flow. Sign in to save configurations.
2. Select the starter. Search by bulletin (for example, 509 for a full-voltage NEMA starter) or start from the existing starter's catalog number. Choose the NEMA size, enclosure type, coil voltage, and options to match the actual starter.
3. Choose the overload type. Pick the Bulletin 592 eutectic-alloy (heater element) overload, not a solid-state overload. Select the trip class:
4. Enter motor data. At the heater element step, enter nameplate FLC and service factor. If the tool asks for ambient conditions, enter them; if it does not, apply the correction yourself (next section) and enter the corrected FLC.
5. Record the recommended heater. The configurator returns a heater catalog number (for example, W48) and usually the quantity, typically three for a three-phase starter.
6. Cross-check against 592-TD010. Find the correct table for your bulletin, size, and enclosure in the index of publication 592-TD010. Confirm the recommended element's listed full-load amperes is nearest your FLC, using the rules below.
7. Add to BOM. Add the starter and heater elements to your BOM, or note them for a separate order if the starter is already installed.

• • Class 20 (Type W) for general-purpose motors — Rockwell's standard.
  • Class 10 (Type J) for hermetic, submersible-pump, or short locked-rotor-time motors.
  • Class 30 (Type WL) for high-inertia loads needing longer acceleration.

Verification rules and adjustments

The selection tables assume a 40 °C ambient and a service factor of 1.15 or higher. Check each condition below; any that applies changes the element.

Selection rules (continuous-duty motors, SF ≥ 1.15)

Condition	Rule
Same temperature at starter and motor	Choose the element whose listed FLA is nearest the nameplate FLC
Starter warmer than motor (≤ 10 °C difference)	If FLC falls between two values, choose the higher
Starter cooler than motor (≤ 10 °C difference)	If FLC falls between two values, choose the lower
Service factor below 1.15	Go one element size smaller than the rules above give
Intermittent-duty motor	Contact Rockwell or your distributor

Ambient correction (temperature difference over 10 °C)

Read a correction factor for the motor ambient (C.F. motor) and for the starter ambient (C.F. controller) from the curve in 592-TD010 for your element type. Then:

FLC_{corrected} = FLC_{nameplate} \times \frac{C.F._{motor}}{C.F._{controller}}

Select the element whose listed FLA is nearest the corrected value. A hot motor shrinks the element; a hot starter enlarges it.

Worked example from 592-TD010: 25 hp, 460 V motor, FLC 34 A, SF 1.15, Bulletin 512 Size 2 (Table 153). Motor at 55 °C, starter at 40 °C. C.F. ratio = 91% ÷ 100% = 0.91, so corrected FLC = 30.9 A. Table 153 lists W64 at 30.0 A and W65 at 32.5 A; 30.0 A is nearer, so select W64.

Final checks

• ☐ Element type matches the trip class (J = 10, W = 20, WL = 30)
• ☐ Table matches the bulletin, size, enclosure, and number of elements
• ☐ Quantity matches the relay (three for most three-phase starters)
• ☐ Configurator result agrees with the manual table check
• Note on the motor list or one-line: motor tag, nameplate FLC and SF, starter catalog number, table used, ambient correction (if any), and heater catalog number.
• Order by catalog number (e.g. W48), in the quantity the relay needs. Check lifecycle status on the product page: some J-type elements are discontinued.
• After installation, confirm the heaters match the record and the reset mechanism operates.
• Type W and WL elements do not meet EU RoHS material restrictions; check before specifying for export equipment.
• Heater Element Specifications, Bulletin 592, publication 592-TD010 — selection rules, correction curve, and all selection tables
• Rockwell Automation Tools — Product Configurator, Advisor, BOM, and ProposalWorks
• Example product page: P8 heater element — shows lifecycle status and lead time per element

The relay trips at 115% of the listed FLA for Type J and W elements, and 120% for Type WL, at 40 °C.

Documentation and ordering

Record the selection so the next technician can verify or replace it without redoing the work.

References

The configurator's screen flow was not verified directly; confirm step names against the live tool when first using this procedure.