User Setting for Voltage & Frequency 
Standard 3-Phase Sensing
on 3 and 4 Pole Units 
Source 1 
Under Voltage "Restore" 
Factory Default: 90% 
This adjustment determines the minimum acceptable 
voltage required to transfer to Source 1. 
Adjust via the SET menu. Range is 85% to 100% in 
1% increments (see page 17). 
Once satisfied, the T timer will begin timing 
to transfer to Source 1. 
Under Voltage "Fail" 
Factory Default: 80% 
This adjustment determines the low voltage threshold. 
Adjust via the SET menu. Range is 75% to 98% in 1% 
increments (see page 17). 
"Fail" must be a minimum of 2 % below "Restore" 
setting. Once voltage falls below threshold, P timer 
begins timing to signal Source 2 Generator to start. 
Under Frequency "Restore" 
Factory Default: 95% 
This adjustment determines the minimum acceptable 
frequency required to transfer to Source 1. 
Adjust via the SET menu. Range is 90% to 100% in 
1% increments (see page 17). 
Once satisfied, the T timer will begin timing 
to transfer to Source 1. 
Under Frequency "Fail" 
Factory Default: 90% 
This adjustment determines the low frequency threshold. 
Adjust via the SET menu. Range is 88% to 98% in 1% 
increments (see page 17). 
"Fail" must be a minimum of 2 % below "Restore" 
setting. Once satisfied, the T timer will begin timing to 
transfer to Source 1. 
Over Frequency "Restore" 
Factory Default: 102% 
This adjustment determines the minimum acceptable 
Over Frequency threshold at which the transfer switch 
is allowed to re-transfer to Source 1. 
Adjust via the SET menu. Range is 102% to 104% in 
1% increments (see page 17). “Restore” must be a 
minimum of 1% below “Fail” setting. 
Over Frequency "Fail" 
Factory Default: 105% 
This adjustment determines the maximum acceptable 
Over Frequency
. 
Adjust via the SET menu. Range is 103% to 105% in 1% 
increments (see page 17).Once exceeded, the P timer 
begins timing to signal the generator to start. 
Source 2 
Under Voltage "Restore" 
Factory Default: 90% 
This adjustment determines the minimum acceptable 
voltage required to transfer to Source 2. 
Adjust via the SET menu. Range is 85% to 100% in 
1% increments (see page 17). 
Once satisfied, the W timer will begin timing 
to transfer to Source 2. 
Under Voltage "Fail" 
Factory Default: 80% 
This adjustment determines the low voltage threshold. 
Adjust via the SET menu. Range is 75% to 98% in 1% 
increments (see page 17). 
"Fail" must be a minimum of 2 % below "Restore" 
setting. Once voltage falls below threshold, T timer 
will be bypassed to expedite the transfer to Source 1. 
Over Voltage "Fail" 
Factory Default: 110% 
This adjustment determines the maximum acceptable 
Over V
oltage. Adjust via the SET menu. Range is 105% 
to 110% in 1% increments (see page 17). Once exceed-
ed, the T timer will be bypassed to expedite the transfer 
to Source 1. 
Over Voltage "Restore" 
Factory Default: 105% 
This adjustment determines the minimum acceptable 
Over V
oltage threshold at which the transfer switch is 
allowed to transfer to Source 2. Adjust via the SET 
menu. Range is 103% to 105% in 1% increments 
(see page 17). “Restore” must be a minimum of 
2% below “Fail” setting. 
Under Frequency "Restore" 
Factory Default: 95% 
This adjustment determines the minimum acceptable 
frequency required to transfer to Source 2. 
Adjust via the SET menu. Range is 90% to 100% in 
1% increments (see page 17). 
Once satisfied, the W timer will begin timing 
to transfer to Source 2. 
Under Frequency "Fail" 
Factory Default: 90% 
This adjustment determines the low frequency threshold. 
Adjust via the SET menu. Range is 88% to 98% in 
1% increments (see page 17). 
"Fail" must be a minimum of 2 % below "Restore" setting. 
Once satisfied, the W timer will begin timing to transfer 
to Source 2. 
Over Frequency "Fail" 
Factory Default: 105% 
This adjustment determines the maximum acceptable 
Over Frequency
. Adjust via the SET menu. Range is 
103% to 105% in 1% increments (see page 17). Once 
exceeded, the T timer will be bypassed to expedite the 
transfer to Source 1. 
Over Frequency "Restore" 
Factory Default: 102% 
This adjustment determines the minimum acceptable 
Over Frequency threshold at which the transfer switch 
is allowed to re-transfer to Source 2. Adjust via the SET 
menu. Range is 102% to 104% in 1% increments 
(see page 17). “Restore” must be a minimum of 
1% below “Fail” setting. 
ZTS / ZTSD Operation and Maintenance Manual (71R-3000) 
GE Zenith Controls 8