HPS Imperator PH250MQMJ Machine Tool Control Transformer, 250 VA, 240x480V Primary / 120x240V Secondary

HPS Imperator PH250MQMJ control transformer, 240/480V primary class. Hammond Power Solutions (HPS) is North America's largest dry-type transformer maker, and the Imperator line is its machine-tool control transformer standard.

Control transformers step panel voltage down to control circuit voltage in industrial machine panels: motor starters, machine tools, and OEM control cabinets. Sizing is by inrush VA of the coil load, which is why panel builders keep the common Imperator frames on the shelf.

New in box. Two available; price is per transformer.

Buying the exact OEM part number keeps fit, rating, and mounting identical to what the machine was designed around.

New surplus, available from King Surplus inventory in Del Rio, Texas.

• Manufacturer: Hammond Power Solutions Inc. (HPS)
• Series: HPS Imperator, Machine Tool Industrial Control Transformer / Transformateur de Controle
• Part number: PH250MQMJ
• Serial number: AC0000136
• VA rating: 250
• Frequency: 50/60 Hz
• Primary voltage: 240x480, 230x460, 220x440 VAC
• Secondary voltage: 120x240, 115x230, 110x220 VAC
• Secondary output current: 2.08 A at 120 V, 1.04 A at 240 V (250 VA divided by the nameplate secondary voltages; the figure is not printed on the plate)
• Temperature rise: 80 deg C
• Terminal markings: primary H1 H3 / H2 H4; secondary X4 X2 / X3 X1
• Agency: UL Listed 252L, file E50394
• Country of manufacture: China (nameplate reads MADE IN CHINA)
• Other nameplate markings, verbatim: PATENT PENDING | 130-9 | INDUSTRIAL CONTROL TRANSFORMER | CUST. REF: (blank) | GUELPH, ONT WALKERTON, ONT BARABOO, WI | 803423077796 | 1918 | Stack This Way Up
• Phase: single phase. NOT printed on the nameplate - the plate carries no phase marking. HPS Imperator machine-tool control transformers are single-phase units and distributor listings for this part number state 1 phase.
• Optional primary fuse kit: PFK2. CARRIED OVER FROM THE PREVIOUS ENTRY AND NOT CONFIRMED. It is not on the nameplate, and HPS literature checked on 2026-09-16 did not confirm the kit number for this part. Do not quote it to a customer without checking HPS's current fuse-kit selection table.
• Spec Basis: verified 2026-09-16 against the transformer's own nameplate as transcribed from all 7 record photographs. Manufacturer, series, part number, serial, VA, frequency, both voltage ranges, temperature rise, terminal markings, the UL listing and the country of manufacture are all printed on that plate and all agree with what the record already held. Record manufacturer (FID 56 HPS) and model (FID 57 PH250MQMJ) agree with it. CORRECTED: the previous entry claimed a CE mark - CE is not on this nameplate. HPS does state a CE mark as standard across the Imperator line in its published literature, so the claim is probably true of the line, but it is not a marking on this unit and has been removed rather than repeated as a nameplate fact. The previous entry also carried "Weight: 8 lb", which is a King Surplus handling figure, not a manufacturer specification, and is also out of step with the roughly 7.5 lb that distributors publish for this part number; it has been taken out of this field.