Allen Bradley509-DOD-7NEMA Size 3 Full-Voltage Non-Reversing Magnetic Motor Starter, 3-Pole, 90 A, 25–50 HP 200–575 V Three-Phase, Eutectic Alloy Overload, Open Type

Product Description

Bulletin 509 starters are designed for full-voltage (across-the-line) starting of polyphase squirrel-cage motors. They combine a magnetic contactor with an overload relay and can be operated from push buttons, float switches, thermostats, pressure switches, snap switches, limit switches or any other suitable two- or three-wire pilot device. This is the NEMA Size 3 build.

Ratings

Continuous current: 90 A, NEMA Size 3Three-phase 60 Hz horsepower: 25 HP at 200 V, 30 HP at 230 V, 50 HP at 460 V, 50 HP at 575 V3 polesCoil burden for a Size 3 (from Allen-Bradley publication 509-6.0): 660 VA inrush / 45 VA sealed on a 2–3 pole motor load; 840 VA inrush / 58 VA sealed on a 4–5 pole motor load

Decoding the designation

In the Bulletin 509 scheme the first letter after the bulletin number is the NEMA size — D = Size 3 — and the base 509-DOD is published by distributors as the Size 3, full-voltage, 120 V AC coil unit with a eutectic-alloy overload relay. The trailing -7 is a factory modification code. Allen-Bradley’s published documentation for this bulletin does not include a public decode table for that suffix, so coil voltage and the auxiliary-contact complement are left blank on this record rather than assumed — both are stamped on the coil and the contact blocks and should be read off the unit before you order.

Eutectic alloy overload — what you are getting and what you must add:
The overload relay on this unit is the melting-alloy (eutectic) type, and the photographs show three heater blocks fitted, each marked AUTO RESET. Two things follow from that. First, trip current is set by the heater elements, and heaters are sized to the motor’s actual full-load amps — the heaters installed here were sized for someone else’s motor, so verify or replace them for yours. Second, automatic reset means the starter will re-close the overload contact by itself once the alloy re-solidifies; on a machine where an unexpected restart is a hazard, you want a manual-reset relay instead, and this is not it.

Renewal parts that keep it in service (Allen-Bradley publication 509-6.0):
Size 3 single-pole contact set (movable contact, spring, front and rear stationary contacts): 40430-300-51Size 3 eutectic alloy overload relay, including test module: 40185-802-01Size 3 operating coil, 115–120 V 60 Hz / 110 V 50 Hz: CD236; 200–208 V 60 Hz: CD249; 230–240 V 60 Hz: CD254; 460–480 V 60 Hz: CD273; 575–600 V 60 Hz: CD278Size 3 contact block cover 40430-457-51; coil cover 40430-454-51; yoke 40430-455-51Stationary contact replacement torque, Size 3: approximately 90 lb-in. Coil cover screws 25–30 lb-inSolid-state alternatives that retrofit to a Size 3 include the SMP-1 (592-A1JD 14–45 A, 592-A1KD 23–75 A, 592-A1LD 66–110 A), the SMP-2 (592-B1JD / B1KD / B1LD) and the SMP-3 (592-C1LD, 20–90 A) — worth knowing if you would rather have phase-loss, jam and ground-fault protection than melting alloy.

Auxiliary contacts

Bulletin 509 starters accept one to four Bulletin 595 auxiliary contact blocks at coil-cover positions P1 to P4, giving up to six auxiliary contacts, and they snap in without tools or extra hardware: 595-A (1 N.O.), 595-B (1 N.C.), 595-BL (1 N.C. late break), 595-AB (1 N.O. + 1 N.C.), 595-AA (2 N.O.), 595-BB (2 N.C.).

Configuration reality — read before buying

This is open-type construction on a mounting plate, as shown in the photographs. It is not an enclosed starter: Allen-Bradley’s own instruction is to install it in a suitable enclosure and keep it free from contaminants. Bulletin 509 is also a non-combination starter — it contains no disconnect and no branch-circuit protection, so a separate disconnecting means and short-circuit protection are required. One starter supplied; no enclosure, no pilot devices, no auxiliary contact blocks beyond those fitted, and no documentation.

Status and interchange

Bulletin 509 is the modern successor to the older Bulletin 709 and remained in production across NEMA sizes 00 to 9 with Class 10, 15, 20 and 30 overload options. Also written 509-DOD-7, 509DOD7, 509 DOD 7, 509-DOD7. The base 509-DOD is the closest published catalogue reference; a 509-DOD is not automatically identical to a 509-DOD-7 because of the modification suffix.

Source-data note: the previous title’s “25-50HP 200-575V AC” range is correct for a NEMA Size 3 and has been retained and itemised by voltage. Series A and Made in USA have been retained. The 90 A continuous rating, coil and contact renewal part numbers, auxiliary contact options, open-type construction and automatic-reset overload configuration were all absent from the record and have been added.