Liebert II - Manual (Page 13)

Operation 9
Form C Dry Contacts—Dual summary alarm Form C (1 N.O. and 1 N.C.) relay contacts are
provided for remote indication of each failed surge current modules. The summary alarm contacts
terminals are located on the PC board inside the unit. Contacts are rated for 5 amps at 240 VAC
with a power factor of 1.0. The states of the Form C Dry Contacts are determined with power
applied. Connection to the Form C Dry Contacts are provided by #18 AWG wires attached to the
status module. The yellow wire is for connection to the NO contact. The blue wire is for connection
to the NC contact. The orange wire is for connection to the common point of the Form C Dry Con-
tacts.
Surge Counter—The Surge Counter monitors line to ground transient voltages. This circuit
totalizes all surges that deviate from the line sine wave envelope by more than 125 volts. The
counter is AC coupled and rejects transient voltages longer than 100µs.
Swell Counter—The Swell Counter monitors all line to line and line to neutral voltages. It is fac-
tory set to record whenever the peak voltage on any normal mode exceeds the MCOV of the TVSS
for more than 100µs. This allows the counter to record temporary line over voltages that many
result from utility switching, line regulation problems, etc.
Remote Monitor Panel—A remote monitor panel is available to provide unit status and alarm
information at a location up to 500 feet away from the Liebert TVSS System. (See Table 4.) Oper-
ation of the Remote Monitor Panel is similar to the unit system monitor panel. The “Enable” posi-
tion of the switch is the normal position, which allows audible alarm operation. The “Disable”
switch position silences the audible alarm. The “Test” position tests the audible alarm and indica-
tor lights. The remote monitor panel requires an external source of power. Standard units are fur-
nished with a six-foot line-cord with a 5-15P NEMA plug.