Elgar sw1850 power supply

[Faringdon]

Hi,
Just been kicked out of the lab as closed for the night.
Failed to get the Elgar sw1850 power supply working.....needed it to test  a 115vac 500w smps.
Do you know why it might have kept tripping out whenever i tried to enable it?....it gave some "limit" type error.
Is there some signal input you have to give to get this thing working.
A  engineer was using it last week, but that guy was off today.

Elgae sw1850 1850 va power supply
http://www.signaltestinc.com/v/vspfiles/assets/datasheet/Elgar_SW_Datasheet.pdf