The type of conduit that is mostly used on transformers and in areas of high vibrations is **RMC** which stands for Rigid Metal Conduit.
Here are some reasons why RMC is preferred in such scenarios:
1. **Durability**: RMC is made of thick metal which provides excellent protection against physical damage and can withstand high levels of vibration.
2. **Protection**: RMC offers superior protection against moisture, chemicals, and other environmental factors, making it ideal for harsh conditions often found near transformers.
3. **Fire Resistance**: RMC is fire-resistant, which is crucial in areas where transformers are present due to the potential fire hazards associated with electrical equipment.
In contrast, options like PVC, EMT, and FMC are not as suitable for areas with high vibrations or around transformers due to their material composition and flexibility, which may not provide the same level of protection and durability as RMC.
