Greases for sliding electric switch contacts must meet the same demands of any mechanical sliding: film strength, appropriate low and high temperature fluid range, and stay-in-place capability. In particular, a switch grease’s ability to prevent wear is critical. Wear debris creates two problems. It can inhibit current flow when the contact is closed, increasing millivolt (mV) drop. When the contact is open, conductive wear debris can cause open circuit resistance (OCR) problems. In either case, switch performance is compromised. When selecting a switch grease, also note that the viscosity of the base oil should complement the contact force of the switch. Low current/low contact force applications require lighter base oils. High current/high contact force applications benefit from more viscous base oils.
Lubricants for arcing contacts.
Because the temperatures reached in an electric arc are sufficiently high to degrade any organic molecule, a lubricant’s tendency to “burn cleanly” is a definite advantage. Greases for arcing contacts should be formulated with fluids and thickeners that degrade with fewer by-products than traditional greases. A recent innovation is the addition of an additive that scavenges surface oxides to reduce contact resistance.
New non-burning switch lubricant technology.
Greases that oxidize under arcing conditions pose a special problem for low load/low current applications. Traditionally, cleaner burning glycols were used to minimize carbon build-up. A new approach to eliminating problems associated with oxidation is to use UniFlor™, non-burning perfluoropolyether-based greases. Dispersed in a non-flammable, ozone-safe, fluorinated solvent, these greases leave a thin film of lubricant, ideal for low load/low current applications. An additional benefit, this thin film does not attract dust and debris.
Lubricants for distribution switchgear.
Lubricants for distribution switchgear, which may remain unactuated for long periods, serve a protective as well as a lubricating role. They should be oxidatively stable over time, water-resistant, and non-migrating. Because high temperatures may be induced by high current flow or high-temperature industrial conditions, wide temperature capability can be important.
A note about damping greases.
Nye damping greases are widely used on the mechanical elements of many switch assemblies. They serve to reduce friction and wear, quiet detents, and give a smooth controlled “feel” to switch operation. See our application summary on Damping Greases for details.
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Lubricants for Sliding Contacts in Electric SwitchesGreases for sliding electric switch contacts must meet the same demands of any mechanical sliding: film strength, appropriate low and high temperature fluid range, and stay-in-place capability.
Our Products
Making your selection.
Selecting the proper grease for a specific switch application is the real challenge. Very subtle differences in grease formulations, which are sometimes counter-intuitive, can result in dramatic performance improvements. The following is a list of greases custom-formulated for a particular application. Additional Nye greases are available to meet a wide range of application requirements. For technical specifications, evaluation samples, questions about any Nye products, or to discuss a lubricant custom-designed for your application — call us at (508) 996-6721.
| General Purpose Lubricants | Temp Range (°C) | Recommended Contact Force (g)** |
Low Current <1 amp |
Medium Current 1-10 amps |
High Current >10 amps |
Salt Water Resistant | Plastic Compatible |
| Rheolube™ 737S | -60 to 120 | 20 |  |
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| Rheolube™ 716HT* | -54 to 175 | 20 | |
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| Instrument Grease 732C* | -54 to 150 | 20 | |
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| Rheolube™ 362HT | -54 to 125 | 50 | |
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| Rheolube™ 789DM* | -40 to 150 | 80 | |
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| Rheolube™ 368 | -40 to 125 | 150 | |
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* Use with caution around polycarbonate, a-b-s resins, Buna N and other ester-vulnerable plastics and elastomers.
** Minimum contact force (g) that must be available for serviceability at -40°C.
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Lubricants for Arcing Contacts |
Temp Range (°C) | Low Contact Force <100g | High Contact Force >250g | Plastic Compatible |
| NyoGel® 782G* | -40 to 100 | |
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| Rheolube™ 748LT | -35 to 100 | |
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| Rheolube™ 731^* | -30 to 100 | |
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| Rheolube™ 731W^* | -30 to 100 | |
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| UniFlor™ 8512 | -50 to 225 | |
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* Use with caution around polycarbonate, a-b-s resins, Buna N and other ester-vulnerable plastics and elastomers.
^ New oxygen scavenging additive.
| New Non-Burning Switch Lubricant Technology | Temp Range (°C) | Characteristics |
| NyeTact® 570H-10 | -40 to 225 | Non-burning grease dispersion for all contacts where mV drop and Open Circuit Resistance can be a problem. |
| NyeTact® 571H-10 | -54 to 250 | Lower-temp version of NyeTact® 570H-10. |
| UniFlor™ 8511 | -50 to 225 | Chemically-resistant, fluorinated grease. Excellent material compatibility. |
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Lubricants for Distribution Switch Gears |
Temp Range (°C) | High Contact Force >250g | Salt Water Resistance | Plastic Compatible |
| Rheolube™ 362 | -54 to 125 | |
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| Rheolube™ 368 | -40 to 125 | |
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| NyoGel® 760D | -40 to 125 | |
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* Use with caution around polycarbonate, a-b-s resins, Buna N and other ester-vulnerable plastics and elastomers.
Because we cannot anticipate or control the many different conditions under which this information and our products may be used, we cannot guarantee the applicability of this information or the suitability of our products in any individual situation. For the same reason, the products discussed are sold without warranty, expressed or implied. Statements concerning the possible use of our products are not intended as recommendations to use our product in the infringement of any patent.
