GE ballast for 175 watt H39/H22 Mercury lamp. We call these IL (independent lighting) transformers.

This one was used in a 6.6 amp arc circuit (series street light circuit). It's rated for up to 10500V.

This one was used in a 6.6 amp arc circuit (series street light circuit). It's rated for up to 10500V.

Same as above

The big can on the pole is an RO (regulated output) transformer. The small can above it is an oil switch. The disconnect to the right,

feeding the oil switch, is open and tagged. This is no longer in use. The primary of this RO is 12000V. It's in our 20.8KV system,

phase to ground or star. This RO puts out a constant 6.6amps and the voltage varies by the number of lights on the series circuit. It

did this with a movable core and a counter balance. If the arc circuit is opened up the voltage goes to the maximum which could be

just over 5000 volts on this one.

feeding the oil switch, is open and tagged. This is no longer in use. The primary of this RO is 12000V. It's in our 20.8KV system,

phase to ground or star. This RO puts out a constant 6.6amps and the voltage varies by the number of lights on the series circuit. It

did this with a movable core and a counter balance. If the arc circuit is opened up the voltage goes to the maximum which could be

just over 5000 volts on this one.

Same as above

Same as above

6.6 amp lamp from arc circuit

If this light burns out, a

wafer between those two

prongs, that insulates during

normal operation, will burn

through when the RO goes

to maximum voltage, closing

the arc circuit back in. These

wafers were referred to as

onion skins.

wafer between those two

prongs, that insulates during

normal operation, will burn

through when the RO goes

to maximum voltage, closing

the arc circuit back in. These

wafers were referred to as

onion skins.

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