You have a few options to get a neutral in your 240V 3-phase 3-wire delta system

Option 1: Isolation Transformer
Install an isolation transformer between the main panel and the lighting panel. The transformer will create a neutral point that can be used to provide 120V power to your loads. This is a relatively expensive option but provides isolation and surge protection.

Option 2: Zigzag Transformer Connect a zigzag transformer to the main panel. This transformer will create a neutral point that can be tapped for 120V power. It is less expensive than an isolation transformer but does not provide isolation.

Option 3: Scott-T Transformer Connect a Scott-T transformer to the main panel. This transformer is similar to the zigzag transformer but uses two single-phase transformers. It provides a neutral point and some isolation, but it is more complex and expensive than the other options.

Option 4: Grounded Delta System Reconnect the transformer on the upstream side of the main panel to create a grounded delta system. This will create a neutral point that can be used for 120V power. This option may not be feasible if the transformer is not accessible or cannot be reconnected.

Recommendation:

Based on your description, Option 1 (isolation transformer) is the most suitable solution for your pumping station. It will provide a safe and reliable way to create a neutral point and isolate your sensitive electronic equipment from the main power supply. Flag for review