We have ~78 underground pull boxes (12ft by 12ft) scattered around our 700m by 1500m yard that are passing 12kV cables through underground ductwork.(i.e. pipes) See figure attached for detailed drawing of layout including pull boxes, station service transformers and control buildings. Recently, water has started seeping into these pull boxes, and this water needs to be pumped out. Only problem is, there is no AC power available inside these pulls boxes to power the pump needed to pump the water out! So the design challenge we’re faced with is to come up with a simple, efficient and cost effective solution that will provide each of these ~78 pull boxes with AC power such as a standard 120V outlets and lighting. The outlets will only need to handle loads as large as the pump and the necessary lighting, nothing else. So far we’ve come up with a couple ideas: 1) Take the 600V (line-line) feed from the station service transformers (denoted SST1 and SST2) and route these to the nearest pull boxes where each individual pull box will have its own separate transformer needed to step down the voltage to the desired 120V. 2) Route the 600V (line-line) feed from the station service transformers (denoted SST1 and SST2) and to a couple strategically placed 600V/120V transformers and supply multiple pull boxes from this one transformer. With this option we could have issues with voltage drop across the 120V cables depending on how far the distances are from the 600V/120V transformer to the pull box. 3) Take the existing 120V AC feed from each of the control buildings within the yard (denoted CBF1, CBF2, CBF3 etc…) and somehow connect this to the surrounding pull boxes. However, there is a problem with this. The cabling for the control buildings is in cable trenches, while the cabling for the underground pull boxes is in underground cable ducts. (i.e. pipes) So in order for us to get a cable from the control building into the pull box, it would require for drastic changes to existing cable trenches in order to route the cable inside the trench to the pullbox. (Unless there is an easier way?) We do have 12kV cables at our disposal coming out of the two switchgear buildings 1 and 2 (denoted SGB1 and SGB2) but transformer needed to get a 120V AC from 12kV may be larger and more expensive than practical. Does anyone else have any other creative/inventive ideas in order to solve this problem, or see any advantages/disadvantages with the three options we’ve come up with so far? I think some group brainstorming is always a good idea! Thanks again! EDIT: I just thought of another idea. How about rectifying the 600V AC (line to line), running it into the pull boxes as DC and converting it back into 120V AC? One rectifier feeding all the DC cables and one inverter per pull box. Just popped into my head and figured I'd throw it out there.