Cable Connections

AUTOMATIC AC CROSSOVER SWITCH

INSTRUCTIONS

Thank you for purchasing the Sterling Automatic AC Crossover Switch, a sophisticated product which will help

you to safely and comfortably switch your AC power sources on board. Before starting to install the unit, please read and understand these instructions completely, in order to avoid any possible safety risks and to avoid any danger of damaging the unit or your boat / vehicle.

All high voltage input and output connections must be totally isolated before working on the circuits or this unit! It is strongly advised that any work being performed on high voltage equipment or circuits must be done by professionals only.

MAIN PRODUCT FEATURES

The Sterling Automatic AC Crossover Switch is a three-stage sequential switch which will automatically switch the AC power sources on board. It will ensure that only one AC power source will be on your boat’s ring mains at any one time, thereby protecting your electrical equipment from possible damage.

The complexity of the system is masked by its easy installation and fully automatic operation. Basically, the unit is a three-stage sequential switch with the channel marked “shore power” as the priority selection. The channel marked “generator” is second, and the channel marked “inverter” is third. This default setting works on the assumption that the boat has shore power, a generator and an inverter. However, some boats may have 2 generators and no inverters, in which case you can simply use the inverter port as another generator port etc. In fact, you can mix and match as you wish. There are a few things which are unique to each channel but these do not affect the channels from being used for an input source other than the default.

It is important to stress that this system operates by itself in fully automatic mode and requires no human intervention. However, for more complicated systems, the Sterling Automatic AC Crossover Switch offers many additional and sophisticated features.

This unit comes set up as standard for use with either 110V or 230V, 40Hz - 60Hz with a current rating of 32A. Each input channel is fused at 32A. For safety, the internal relay control system is rated at 40A continuous.

INSTALLATION (see Fig. 1)

Install the unit as per wiring diagram. Ensure that the cables being used have the correct rating and size for the power being applied. Fit in a cool, dry and well ventilated place.

Remove the screws from each end of the unit to remove the end caps. The p.c.b. can slide about 1 - 2 inches either way to expose the screw connectors for installing the cable. Slide the cables through the slots in the end caps (If required, you can make the openings slightly bigger.). For 32A three-core cable, the outer cable sheath will need to be removed to enable the smaller internal insulated cables to be worked on with ease.

Connect cables as per drawing. Run the wires through the cable ties. When the wiring is completed, the cable ties can be pulled tight to lock and fix the wiring. Replace the end caps.

System Components

AShore power input: Connect live to L and neutral to N on the screw terminals. The fuse beside the connection block is a 32 amp fuse. In the event of this fuse blowing, simply replace it and check why the rating of the equipment was exceeded. Please ensure that adequate cable is used to cover the usage on the boat. This channel is the only channel with reverse polarity warning.

BGenerator input: Connect live to L and neutral to N on the screw terminals. The power source does not necessarily have to be a generator. It could also be an inverter or any other a/c power source; it is simply the next channel which the system will engage, when and if the shore power is disconnected. This channel has a 10- second delay in order to allow the generator to fire up and to reduce the high voltage surge associated with generator startups. (All other channels work on about a 1 second delay.)