Description
Phenolic Insulator — Part #K78166
Part #K78166 is the OEM phenolic insulator that connects the grounding cable to the circuit board inside an . It’s molded from phenolic, a rigid thermoset that insulates well and shrugs off heat, so the connection stays clean and the monitor keeps reading the ground path correctly.
The kit has what you need for a field repair: the white phenolic insulator and nut, the brass cable connector, and the internal wiring. It fits both styles of , so you don’t have to match cable generations.
Replace it when the connector cracks, the insulator chips, or the monitor starts giving intermittent or failed readings that point to the cable-to-board connection and not the clamp. Phenolic is the material here for a plain reason: it takes daily clamp handling without cracking or going conductive.
| Spec | Detail |
|---|---|
| Part number | K78166 |
| Material | White phenolic (thermoset) insulator + nut |
| Includes | Phenolic insulator, nut, brass cable connector, internal wiring |
| Compatibility | Both styles of STS grounding cable |
| Dimensions | 2.5 × 4.5 × 0.875 in |
| Weight | 0.112 lbs |
| Made in | Budd Lake, NJ, USA |
Not sure which part you need? or with your system’s part number. It’s one of several we stock for STS 300 systems.
Frequently Asked Questions
What is a phenolic insulator?
A phenolic insulator is a part molded from phenolic resin, a thermoset plastic that resists heat and doesn’t conduct electricity. In an STS 300, it connects the grounding cable to the circuit board and keeps that junction isolated.
Is a phenolic insulator the same as a phenolic bushing?
For this part, yes. “Phenolic bushing” and “phenolic insulator” describe the same insulating connector. STS Part #K78166 fits both styles of STS grounding cable.
How do I replace the phenolic insulator on an STS 300?
Replace it when the connector is cracked or the readings turn intermittent. The K78166 kit includes the insulator, nut, brass connector, and wiring, and it connects the grounding cable to the circuit board.
Will it fit my STS grounding cable?
Yes. Part #K78166 works with both styles of STS grounding cable.
