Description
Keystone Dry Film HID Pulse Start Metal Halide Capacitor, 400W, 26uF, 330V
Keystone 400W Pulse Start Metal Halide Replacement Capacitor (CAP-400MPS)
The Keystone CAP-400MPS is an industrial-duty, metallized AC oil-filled replacement capacitor engineered specifically for 400-watt pulse start metal halide (ANSI M128, M131, M135, M155) ballast circuits. Engineered to deliver power factor correction (≥90% HPF) and ensure stable arc maintenance across CWA systems, this component features a hermetically sealed aluminum oval can, an internal discharge safety bleed resistor, and standard 1/4″ quick-connect spade terminals designed for commercial high bays, sports floodlights, and industrial area luminaires.
Key Features & Performance Benefits
- Power Factor Correction: Optimizes line impedance and compensates for reactive inductive loads in 400W CWA circuits, maintaining high power factor (≥0.90) and preventing excessive current draw.
- Internal Safety Bleed Resistor: Factory-installed discharge resistor drains hazardous stored high-voltage residual DC charge within minutes after circuit shutoff to ensure safe servicing.
- Hermetic Aluminum Can Construction: Seamless extruded oval aluminum housing with a rolled compression header seal prevents dielectric fluid leakage and withstands continuous thermal stresses.
- Universal Retrofit Compatibility: Matches standard physical dimensions, mounting brackets, and electrical ratings across Keystone, Philips Advance, and Universal core-and-coil 400W ballast kits.
- Safety & Compliance: UL Recognized component (UL 810), CSA certified, utilizing environmentally friendly non-PCB dielectric fluid and an internal pressure-sensitive interrupter (PSI) for safe failure disconnect.
Electrical & Physical Data
| Specification | Details |
|---|---|
| Primary Lamp Rating | 400W Pulse Start Metal Halide |
| ANSI Ballast/Lamp Code | M128, M131, M135, M155 (Pulse Start) |
| Capacitance | 26.0 µF ±3% (Microfarads) |
| Voltage Rating | 330V AC |
| Operating Frequency | 50 / 60 Hz |
| Terminal Style | 1/4″ (0.250″) Quick-Connect Spade Terminals |
| Dielectric Medium | Non-PCB Biodegradable Oil Fluid |
Frequently Asked Questions
What does "CAP-400MPS" stand for in Keystone's catalog?
"CAP" designates a standalone replacement HID capacitor, "400" denotes the 400W lamp rating, "M" signifies Metal Halide chemistry, and "PS" specifies Pulse Start circuit operation (ANSI M128/M131/M135/M155).
How does the CAP-400MPS differ from a standard 400W probe-start capacitor (CAP-400MH)?
Standard 400W probe-start (ANSI M59) ballasts typically require a 24.0 µF / 400V AC capacitor. Pulse start 400W ballasts require a 26.0 µF rating (commonly rated at 360V AC or 400V AC). Always verify the microfarad rating on the existing ballast label before replacing.
Does this capacitor include the starter ignitor?
No. The CAP-400MPS is strictly the standalone capacitor unit. Pulse start ballasts require an external electronic pulse ignitor (starter) in addition to the capacitor to deliver the 3–4kV starting pulse to the lamp.
Spec Sheets
Download the official manufacturer documentation and specifications:
Additional Information
Our Part No: |
CAP-400MPS |
Mfr Part #: |
CAP-400MPS |
Manufacturer Material Code: |
YGX-71 |
Brand: |
Keystone |
Fixture Type HID: |
PS Metal Halide MH Capacitor |
Lamp: |
400W M128, M131, M135, M155 HID Pulse Start Metal Halide |
Type: |
Dry Film |
Watts: |
400W |
Voltage: |
330V |
Microfarad: |
26μF |
Dimensions: |
1.57" Dia. x 3.66" H |
Start Method: |
Pulse Start |
Product Data Sheet: |
See PDF Link Provided |
Energy Certification: |
RoHS |
Case Size: |
10 |
