Hi ppl. This is my 1st post but not last i hope!
I'm testing a small site the location is on 5th floor.
Its new installation but building is existing - so is the electrical source of all building. Down in basemant its 11 Kv and 3 step down transformers to 400. They have UPS and "dirty power"
My board is fed from sub - boar witch is fed from UPS source. There are 3 UPS sources and i tested 2 different boards from diferent UPS sources and for som reason Zs for L1 is very high on roof its 0.76 (one week) 0.66( next week) L2 and L3 (0.16 and 0.19 ).
Board on 5th floor is from other UPS source ( wich is fed directly from buss bar)L1 was 0.18 when i did the incoming cable only, and 0.30 when i connected 40 circuits) L2 and L3 was low 0.9 and 0.8 before adding circuits and went up by 0.05 ohms when installed them 40 circuits.
Anyone have any good explenation why from bouth sources L1 is much higher than L2 and L3.
I'm testing a small site the location is on 5th floor.
Its new installation but building is existing - so is the electrical source of all building. Down in basemant its 11 Kv and 3 step down transformers to 400. They have UPS and "dirty power"
My board is fed from sub - boar witch is fed from UPS source. There are 3 UPS sources and i tested 2 different boards from diferent UPS sources and for som reason Zs for L1 is very high on roof its 0.76 (one week) 0.66( next week) L2 and L3 (0.16 and 0.19 ).
Board on 5th floor is from other UPS source ( wich is fed directly from buss bar)L1 was 0.18 when i did the incoming cable only, and 0.30 when i connected 40 circuits) L2 and L3 was low 0.9 and 0.8 before adding circuits and went up by 0.05 ohms when installed them 40 circuits.
Anyone have any good explenation why from bouth sources L1 is much higher than L2 and L3.