ABB Zenith
27
ZTSCT / ZBTSCT Operation & Maintenance Manual
600-1200 AMP
1) Automatic
a) Manually operated Bypass Switch contacts
(BN/BE) are open and ATS is supplying load.
b) Disconnect Switch (DS) is in Auto.
2) To Bypass ATS
a) Open bottom cabinet door and turn DS to Inhibit.
b) Turn Bypass Selector Switch (BSS) to same power
source as ATS
c) Position manual bypass handle (MBH) upward.
3) To Test ATS
a) Bypass per above instructions.
b) Rotate crank mechanism counter-clockwise until
ATS test light is illuminated.
c) Turn DS to Auto.
d) Test Switch (TS) on bottom cabinet door will allow
electrical operation of ATS.
4) To Isolate ATS
a) Bypass per above instructions.
b) Rotate cank mechanism counter-clockwise
until ATS Isolated light is illuminated.
5) To Remove ATS
a) Bypass and isolate per above instructions.
b) Disconnect multipin plugs and external
connections to ATS.
c) Rotate four power panel latches to vertical
position, slide ATS forward and lock mechanism
in place.
d) ATS can now be removed from cabinet.
6) To Reconnect ATS
a) Place ATS in slide mechanism.
b) Unlock slide mechanism. Slide ATS over power
panel latches and rotate latches to horizontal
position.
c) Turn DS to Inhibit.
d) Manually position ATS into same source
as Bypass Switch.
e) Reconnect multipin plugs and external
connections to ATS.
f) Rotate crank mechanism clockwise until
ATS Test light is illuminated.
g) Turn DS to Auto and use TS to electrically
operate ATS.
h) Turn DS to Inhibit.
i) Move ALH to Auto location.
j) Turn DS to Auto and open Bypass with MBH.
k) ATS is now fully automatic.
Notes:
1. DS in Inhibit will prevent ATS electrical operation.
2. Do not use excessive force on mechanical handles.
3. Figures depict Bypass Source 1. Sequence is the same for Bypass Source 2.
4. When ATS is in Test or Isolate, Bypass Switch is manual transfer switch to either available source
(indicated on light panel).
5. To operate Bypass Switch when ATS is in Test or Isolate:
a) Move MBH downward (to open Bypass Contacts BN/BE).
b) Turn BSS to opposite power source.
c) Move MBH upward to close into selected power source.
Legend:
1. BP - Bypass switch (indicated by contacts BN/BE) is a three position switch.
2. ATS - Automatic Transfer Switch.
Sequence of Operation
(cont’d)
Figure 15
