Is my KWH Meter broken?

please help me...
i have a problem that confuse me.
when my 3 phase 4 wire wye circuit watt hour
meter loaded by an arc welding machine (it's a 1 phase machine),
the induction type watt hour meter act so weird. The disc rotation
reverse slowly for a few moments, and then stop, and then move forward very
slowly (mostly it don't move at all), though current measure in 2 phase
is high (4 A in phase 1, 14 A in phase 2, and i forgot to measure
current in phase 3). The watt hour meter consist of 3 element (3 voltage
coil and 3 current coil, but only 2 rotating disc. one for 2 pair of
voltage and current coil, and the rest is for 1 pair of voltage and current
coil). Watt hour meter is just been calibrated, and install to replace
the old watt hour meter that broken. It's a Krezik presov watt hour
meter. What i wanna ask is:

1. What cause a induction watt hour meter's rotating disc to reverse?
especially for 3 phase watt hour meter, what can cause errors on it? is
there any possisilities that it cause by 2 disc that has by the meter?
(cause i see in another meter, they have 3 disc for 3 element).

2. If power factor is low in one phase (ex: 0,5) and more than 0,5 (ex:
0,8) in another phase, can it cause watt hour meter to revers or give
an error reading? (since the load is a 1 phase induction motor that have
low PF)

3. Is there any load that have leading power factor? If the PF is
leading, will the watt hour meter reverse?

4. if we have Xc higher than Xl to compensate lagging PF, will it has
leading PF?
what the effects to wat hour meter?

5. Is harmonics effects on induction watt hour meter is high enough to
cause errors?

6. Do you have a good papers or article that can help me understand how
induction watt hour meter works? especially for 3 phase 4 wire wye
circuit.

Thanks before, for reading and reply my posting. Sorry for my bad
english, hope you understand.....

sorry if i'm getting it in the wrong section of this forum
i can't get it fit to other topic :D