Power supply series connection: possible fault

[jmt]

I recently picked up a HP E3617A from ebay. I went to connect it in series with my HP E3615A, since they are both floating power supplies, and I noticed an arch when I attempted to connect the wire between them (E3617A (-) to E3615A (+)). Both power supplies had their voltage and current limits on the absolute lowest setting. I turned them both off and measured 36V between each of the E3617A terminals and ground. I shorted this out with a resistor until it read under 1V. Then I connected the two power supplies as before except they were both off. When I turned them on I tripped the circuit breaker. Something is certainly wrong here.
I unplugged both power supplies and measured the following:

• Steadily increasing resistance between either terminal and ground on the E3617A. A capacative short?
• After shorting the terminals, a steadily increasing voltage between either terminal and ground on the E3617A. After 1 minute it is at 17mV.

For comparison, the E3615A shows an open circuit between ground and the terminals (as expected), but also shows the steadily increasing voltage.

Did I connect them incorrectly? What else should I test to help find the fault? I'm relatively new to power supplies so any help would be greatly appreciated.

Update:
As soon as I turn the E3617A on, the 36V between the terminals and ground appears. If I crank the voltage to the max (60V) then I read 90V! With the E3615A, about 300mV is measured.

[Rerouter]

As i do not own the supplies, i will point out some tests you can start with,

1. measure the resistance between the negative terminal and the ground terminal with the supply off, (leave it off for a few minutes to dissipate any voltage difference) if the value is high, then the supply is floating, if it is low, it may have a switch to select a hard ground link or a strap on a rear set of terminals etc,

2. Turn it on, add a resistance (e.g. 47K) between positive and ground, if the negative terminal shifts below ground (-V) and the positive equals ground it is floating, if the negative stays matched the ground then there may be a setting