Monarch ACE-S50SD Series Centrifugal Pump Square Flange & Repair Parts
Monarch Industries ACE-S50SD (1/2 HP) Square Flange Centrifugal Pump
The Monarch Industries ACE-S50SD is a compact and efficient 1/2 HP End Suction Centrifugal Pump designed for dependable water circulation and pressure boosting. As the entry-level model in the premium ACE-S Series, it features a Square Flange motor mounting system, making it a favorite among service technicians and homeowners for its ease of maintenance and robust design.
This pump is engineered with a heavy-duty cast gray iron casing and a precision-molded enclosed glass-filled Noryl impeller. This composite impeller is reinforced with a stainless steel hub, providing a smooth surface that significantly improves hydraulic efficiency compared to standard cast iron impellers. With a 1-1/4″ NPT suction port and 1″ NPT discharge, the ACE-S50SD is perfectly sized for residential irrigation and general water transfer applications.
Key Features of the ACE-S50SD
- 1/2 HP Efficiency: Powered by a 3600 RPM, single-phase, Square Flange motor (Dual Voltage 115/230V) with thermal overload protection.
- High-Performance Impeller: The glass-filled Noryl impeller creates a smooth waterway for maximum flow and is resistant to corrosion and mineral buildup.
- Square Flange Motor: Utilizes the industry-standard Square Flange interface, allowing for quick motor replacement or service.
- Bearing Protection: A shaft flinger and large drain hole in the adapter bracket prevent moisture from pooling and damaging the motor bearings.
- Durable Sealing: Standard Buna/Carbon-Ceramic mechanical seal ensures a tight, leak-proof seal.
- Maintenance Friendly: Drain plugs are conveniently located to allow for easy winterization to prevent frost damage.
Common Applications
The ACE-S50SD is an excellent choice for:
- Garden Irrigation: Powering small-to-medium residential sprinkler systems.
- Water Transfer: Moving water from rain barrels, cisterns, or shallow wells.
- Pressure Boosting: Boosting line pressure for household use.
- Light Industrial: General clear water circulation and transfer duties.
Technical Specifications & Performance
Performance Chart
Total Head in Feet vs. Capacities in U.S. GPM
| HP | Model | 20 ft | 30 ft | 40 ft | 50 ft | 60 ft |
|---|---|---|---|---|---|---|
| 1/2 | ACE-S50SD | 46 | 38 | 32 | 24 | 15 |
Model Specifications
| Model No. | Order No. | HP | Suct. NPT | Disch. NPT | Electrical Characteristics | Ship Wt. (lbs.) |
|---|---|---|---|---|---|---|
| ACE-S50SD | 614561 | 1/2 | 1-1/4″ | 1″ | 1/60/115/230V | 31 |
Description: Single phase motor with built-in thermal overload protection. Stainless steel shaft or replaceable sleeve.
Dimensions (Inches)
| Model | Suction | Discharge | CP | D | E | F | H | L | M | N | OP | X | Y |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ACE-S50SD | 1-1/4″ | 1″ | 13.75 | 4.00 | 4.88 | 3.00 | 7/16×15/16 | 5.53 | 3.69 | 4.00 | 8.90 | 4.90 | 2.63 |
Repair Parts
| Ref. | Code # | Qty. | Description |
|---|---|---|---|
| 1 | 437842 | 1 | Casing (Fits 1/2 HP – 1 HP) |
| 2 | 433106 | 1 | Impeller (Glass Filled Noryl) |
| 3 | 437890 | 1 | Seal Plate |
| 4 | 438245 | 1 | Bracket |
| 5 | 246801 | 1 | End Cap |
| 15 | 164651 | 2 | Stud 3/8″ x 2″ |
| 16 | 164641 | 2 | Stud 3/8″ x 1 3/4″ Zn Pl. |
| 17 | 227830 | 4 | Nut Hex. 3/8 UNC Zn. Pl. |
| 18 | 227830 | 4 | Nut Hex. 3/8″ Zn. Pl. |
| 23 | 176230 | 4 | Spring Washer 3/8″ Zn Pl. |
| 25 | 185620 | 2 | Pipe Plug 1/4″ NPT Zinc Plated |
| 26* | 193914 | 1 | Gasket (Fits 1/2 HP – 1 HP) |
| 27* | 191790 | 1 | Flinger |
| 31* | 240250 | 1 | Mech. Seal MS-25 |
| 34 | 204073 | 1 | Motor 1/2HP 1Ø 115/230V |
Frequently Asked Questions
What is the difference between the ACE-S50SD and the standard ACE-50?
The primary difference is the motor and impeller. The ACE-S50SD uses a “Square Flange” motor and a smooth Noryl impeller, whereas the standard ACE-50 typically uses a “C-Face” motor and a cast iron impeller.
Does the ACE-S50SD come with a power cord?
No, these pumps are typically hard-wired into the electrical system. The motor is dual voltage (115/230V) to accommodate different power supplies.
What is the correct impeller part number for the ACE-S50SD?
The correct replacement impeller for the 1/2 HP model is Part #433106. Please verify your model number before ordering, as other HP models use different impellers.
Is this pump self-priming?
No, end suction centrifugal pumps like the ACE-S series are not self-priming. The suction line and casing must be filled with water before operation. A foot valve is recommended on the suction line to maintain prime.