MSH

Supported Applications

The Omega MSH Series consists of mica-insulated strip heaters designed to provide uniform heat transfer to flat surfaces. These economical and reliable heat sources are utilized in a wide range of industrial and commercial heating applications, including food warming equipment, packaging machinery, blow molding systems, testing apparatus, vulcanizing presses, vending machines, hot plates, ovens, molds, kettles, and incubators.

Operating Conditions & Performance

The MSH series features a heating element composed of nickel-chrome resistance ribbon wire wound on a specially selected mica strip. This construction provides even heat distribution with excellent thermal conductivity and dielectric strength. The heaters operate within specific temperature limits based on the sheath material: rust-resistant steel supports maximum sheath temperatures up to 480°C (900°F), while stainless steel options support temperatures up to 650°C (1200°F). Electrical specifications include a maximum voltage of 480V. Nominal watt density ranges from 5 to 45 Watt/in² (0.8 to 7.0 Watt/cm²); however, when UL and CSA approval is required, the maximum watt density is limited to 38 Watt/in² (5.9 Watt/cm²). Tolerances are defined as ±10% for resistance (-5%) and ±5% for wattage (-10%).

Configuration Options

The series offers extensive configuration options regarding sheath materials, dimensions, terminations, and special features to accommodate diverse installation requirements.

• Sheath Materials: Standard rust-resistant steel is available for general applications. Optional stainless steel or aluminum sheaths are offered for corrosive atmospheres or higher temperature service up to 650°C (1200°F).
• Dimensions: Heaters feature a nominal thickness of 4.76 mm (3/16"). Minimum width is 15.88 mm (5/8") with a maximum length of 1829 mm (72"). Width tolerance is ±0.79 mm (1/32"); length tolerances vary by size, ranging from ±1.59 mm (1/16") for lengths up to 610 mm (24") to ±3.18 mm (1/8") for longer units.
• Termination Types: Configurations include screw terminals and lead wire terminations.
  • Screw Terminals: Type T1, T2, T3; Low-profile button types B, B1, B2, B3; High-temperature quick-disconnect plug P1.
  • Lead Wire Terminations: Types W1 (wire braid), W2/W3 (flexible stainless steel braided leads), and L1/L2/L3 (flexible lead wire exiting top or ends).
  • Abrasion Resistant Terminations: Armor cable types R1, R2; Galvanized or stainless steel cables with crimped, tack welded, or full silver brazing connections.
• Additional Features: Options include Igloo™ ceramic terminal covers and custom engineered designs such as disc heaters, ring heaters, irregular shapes, sinuated (serpentine) element design, non-metal sheath open elements, and distributed wattage configurations.

Key Product Differences

The MSH series is distinguished by its mica insulation technology and specific construction tolerances. Standard models utilize a specially treated rust-resistant steel sheath for physical strength and high thermal emissivity. For applications requiring higher temperature resistance or corrosion protection, the stainless steel variation extends the maximum operating limit to 650°C (1200°F). Electrical connections vary by strip width: strips up to 25.4 mm (1") wide utilize 8-32 threads for screw terminals, while wider strips use 10-32 threads. Maximum amperage ratings differ by termination style, with lead wire terminations rated at 10 A and screw terminations supporting up to 25 A depending on thread size.

Installation variations include models available with mounting slots for surface applications or without slots for insertion into milled surfaces. The series is UL recognized (File E65652) and CSA certified (File 043099) in many design variations, though specific approval status must be specified at the time of ordering.