Icecap 660..NO or VHO?

[nickb]

According to Fulham tech support, the Workhorse 7 is not approved to drive multiple VHO bulbs in either series or parallel. They reported that the current rating of the ballast is such that it can not sustain VHO levels. The rating of 220W is based on peak power, not throughput. If you check their wiring diagrams, you will see that the give diagrams for driving 2 NO or PC tubes but not for 2 VHO tubes.