Ametek SPS A Series Operation Manual page 70

Operation
higher output voltage range is required, contact the Sales
Department or Customer Service for availability.
•
The maximum allowable current for a series string of power
supplies is the rated output current of a single supply in the string.
•
Remote sensing should not be used during series operation.
•
A free-wheeling diode (power diode capable of the maximum
current of the series set connected in parallel, but reverse biased)
is recommended to protect against sinking current into a supply
should one supply be "ON" while the other is "OFF." (See Section
2.6.1).
3-28
AMREL SPS-A Series
M550129-01 Rev A