An Allen-Bradley PowerFlex catalog number packs the drive family, voltage class, output-current rating, frame, enclosure, and options into one string, and the two product lines do not use the same scheme. The 520-series (25A = PowerFlex 523, 25B = PowerFlex 525) is dash-delimited, like 25B-B2P5N104. The 750-series (20F = 753, 20G = 755, 21G = 755 with Options) is a fixed 18-character string with no dashes, like 20G11RB2P2JA0NNNNN. Read the wrong format against the wrong rules and you get a plausible-looking but wrong answer.
This guide explains what the PowerFlex Drive Decoder resolves: how to split each format position by position, why the rating field is an output current and not a horsepower, why the 523 and 525 share the same Normal-Duty rating for a given code, why 750-series HP/kW changes with voltage, and why a 750 enclosure or braking code that is wrong for the frame is an impossible drive rather than a typo.
Two Formats: 520-Series Dash vs 750-Series Fixed String
The first thing the decoder does is read the prefix (positions 1-3) and branch, because the formats are not interchangeable:
| Prefix | Family | Format | Example |
|---|---|---|---|
| 25A | PowerFlex 523 | Dash-delimited 520-series | 25A-B048N104 |
| 25B | PowerFlex 525 | Dash-delimited 520-series | 25B-B2P5N104 |
| 20F | PowerFlex 753 | Fixed 18-char 750-series | 20F11RB2P2JA0NNNNN |
| 20G | PowerFlex 755 | Fixed 18-char 750-series | 20G11RB2P2JA0NNNNN |
| 21G | 755 with Options | Fixed 18-char 750-series | 21G14*C460JN0NNNNN |
The 520-series code is a prefix, a dash, then a body of voltage letter, 3-character rating, enclosure (N), interface, EMC filter, and braking. The 750-series code is a fixed run of 18 characters with positions for family (1-3), frame (4), input type (5), enclosure (6), voltage (7), output-current rating (8-10), filtering (11), dynamic braking (12), door HIM (13), and options (14-18). The decoder recognizes legacy families (PowerFlex 4, 40, 400, 70, 700, 7000, 700S, and the 527 sibling) by prefix and names them, but does not decode their ratings.
The Rating Field Is an Output Current, Not Horsepower
This is the trap that catches the most people. The rating field is the drive's output current in amps, not its horsepower. In a 520-series code the three characters after the voltage letter are amps with 'P' as a decimal point: 2P5 is 2.5 A, 6P0 is 6.0 A, and a 3-digit number like 048 is 48.3 A. In a 750-series code positions 8-10 are the current, with 'K' marking thousands, so 2K1 is 2150 A.
The decoder reads the current as an opaque lookup key and pulls the rated amps, HP, and kW from Rockwell's published tables. It never does arithmetic on the code itself, so it cannot confuse 048 (48.3 A) with 48 HP. Size the motor on full-load amps against the drive output current, then check the published HP/kW as a sanity figure, not the other way around.
523 vs 525: Same Normal-Duty Rating for a Shared Code
Rockwell's 520-series ratings table lists two HP/kW pairs per drive, and it is easy to misread them. They are Normal Duty and Heavy Duty columns for one drive, not separate 523 and 525 columns. For a shared current code the PowerFlex 523 and 525 publish the same Normal-Duty HP/kW. The decoder reports the Normal-Duty figure.
| Code | Output current | Normal-Duty (523 and 525) | Heavy-Duty (same drive) |
|---|---|---|---|
| B048 (240V 3ph) | 48.3 A | 15 HP / 11 kW | 10 HP / 7.5 kW |
| E022 (600V 3ph) | 22 A | 20 HP / 15 kW | 15 HP / 11 kW |
| D043N114 (480V 3ph) | 43 A | 30 HP / 22 kW | 25 HP / 18.5 kW |
So 25A-B048N104 and 25B-B048N104 both decode to 48.3 A and 15 HP / 11 kW Normal Duty. The genuine catalog difference between the families is not horsepower: it is that a few low-current codes, notably the 1.6 A '1P6', are listed only for the 523, and that the 525 adds embedded EtherNet/IP, Safe Torque Off, and position/velocity control. Typing 25B-V1P6N104 returns invalid, because there is no 1P6 row for the 525.
750-Series HP/kW Is Voltage-Dependent
On the 750-series the same output-current code yields different HP/kW at different voltage classes, because horsepower scales with voltage at a given current. The decoder keys the rating on family plus voltage plus code so the right power comes back for the supply (position 7 is the voltage letter):
| Voltage code (pos 7) | Voltage class | Published unit |
|---|---|---|
| B | 240V AC (208V AC) / 325V DC | HP and kW |
| C | 400V AC / 540V DC | kW (HP often not published) |
| D | 480V AC / 650V DC | HP (kW often not published) |
| E | 600V AC / 810V DC | HP |
| F | 690V AC / 932V DC (not UL Listed) | kW |
The 753 (20F) covers Frames 1-7 up to about 400 HP / 270 kW; the 755 (20G) extends to Frames 1-10 and the high-power cabinet range. Because the published tables print HP on the 480V/600V columns and kW on the 400V/690V columns, the decoder shows whichever Rockwell published for that code and voltage and does not convert the missing one. A 21G14*C460JN0NNNNN, for example, returns 460 A and 250 kW at 400V with HP not published, which is exactly what the C-class (400V) table prints.
Frame-Gated Enclosure, Braking, and HIM: Impossible Combinations
The strongest part of the 750-series decode is catching field combinations that cannot exist. The position-6 enclosure code is frame-gated:
| Enclosure code (pos 6) | Meaning | Valid frames |
|---|---|---|
| R | IP20 / Open | Frame 1 |
| F | Flange (Type 4X/12 back) | Frames 2-5 |
| G | IP54 / Type 12 | Frames 2-7 |
| N | IP20/IP00 / Open | Frames 2-7 |
| B/J/K/L/P/W/Y/T | Cabinet codes (21G) | Frames 8-10 |
An enclosure code used outside its frames is reported hard-invalid: 21G14NC460JN0NNNNN fails because enclosure N is a Frames 2-7 code on a Frames-8-10 cabinet drive. Two more positions are gated the same way. Dynamic-braking code A (internal resistor/transistor) is a Frames 1-7 option, so it is impossible on Frames 8-10, which require N: 21G14BC460JA0NNNNN fails on the braking field. And the door-HIM digit at position 13 must be 0, 2, or 4, so 21G14*C460JN5NNNNN fails on an invalid HIM. In every case the decoder names the conflicting field and keeps the verdict invalid even if a rating row otherwise resolves.
The EMC Filter, and What the Decoder Will Not Do
On the 520-series the trailing N104 vs N114 is the EMC filter: N104 is no filter, N114 has the EMC filter installed. The filter ties line-to-ground capacitance, so the N114 variant should not be used on an ungrounded/IT or corner-grounded delta supply without disconnecting the filter. The decoder keys the rating on the filter variant so the N104 and N114 rows never blur together.
Two honesty boundaries are worth knowing. First, the 750-series ratings transcribed here are extensive but the table may not contain every published code; when a code is structurally sound but absent, the decoder returns the structural decode with a clear instruction to verify the current, Normal-Duty and Heavy-Duty HP/kW against 750-TD001, rather than inventing a number. Second, this is a reference decode, not an engineering authorization. It does not size a motor for your load, certify a substitution, approve an enclosure for an environment, or authorize an installation. Verify every decoded value against the drive nameplate and current Rockwell documentation, and confirm Normal-Duty versus Heavy-Duty for your actual load, before ordering or installing.