For the HVAC manufacturer...
Mounted in an insulating ceramic base, a one shot, hi-limit with configurations to suit your requirements...
RD Series Tear Drop Style
The TCO responds to temperature by interrupting an electrical circuit when the operating and /or environmental temperature exceeds the thermal rating of the fuse. This is accomplished when the organic pellet experience a phase change, allowing the spring activated contacts to permanently open the circuit.
The electrical resistance of an RD Series thermal cut-offs is comparable to that found in an equal length of 18 gauge solid copper wire. With proper air flow, heat generation below 15 Amperes is minimal. Above 15 Amperes, the upper limit on current capacity will depend on the environment for each specific application.

| Type | Functioning Temperature (Tf) and Tolerance |
Holding Temperature (Th) |
Maximum Temperature Limit (Tm) |
Safety Approval | ||
|---|---|---|---|---|---|---|
| ℃ | ℉ | ℃ | ℃ | ℃ | ||
| RD070 | 72 | 162 | +0/-4℃ | 65 | 115 | UL |
| RD076 | 77 | 171 | +0/-4℃ | 67 | 150 | |
| RD081 | 84 | 183 | +0/-4℃ | 76 | 115 | |
| RD090 | 93 | 199 | +0/-6℃ | 85 | 315 | |
| RD098 | 100 | 212 | +0/-4℃ | 93 | 130 | |
| RD103 | 104 | 219 | +0/-4℃ | 98 | 315 | |
| RD108 | 109 | 228 | +0/-4℃ | 103 | 315 | |
| RD115 | 117 | 243 | +0/-4℃ | 110 | 130 | |
| RD118 | 121 | 250 | +0/-6℃ | 113 | 315 | |
| RD125 | 128 | 262 | +0/-4℃ | 119 | 180 | |
| RD139 | 141 | 286 | +0/-6℃ | 134 | 170 | |
| RD165 | 169 | 336 | +0/-6℃ | 162 | 270(120V) 210(250V) | |
| RD181 | 184 | 363 | +0/-4℃ | 174 | 210 | |
| RD213 | 216 | 421 | +0/-4℃ | 210 | 375 | |
| RD226 | 228 | 442 | +0/-6℃ | 210 | 260(120V) 230(250V) | |
| RD242 | 240 | 464 | +0/-6℃ | 212 | 375 | |
| Voltage(AC) | Resistive Current | Inductive Current | |||
|---|---|---|---|---|---|
| (Vr) | (Ir) | (Ib) | (Ir) | (Ib) | |
| UL | 120V / 250V | 16.7A | 25A | - | - |
| 120V for only D139 | All types except for D139,D226,D230 |
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*<Note>All types are RoHS compliant.