Instruction Leaflet
30-470 (E)Page 7
Table 1  Interrupting, Closing and Withstand Rating 
Robonic Type A
Robonic
Continuous rms symmetrical amperes
Rating 600 Vac 480 Vac 120,208,240 Vac
30 to 100 amps 14,000 14,000 18,000
150 to 1000 amps 22,000 30,000 42,000
1200 to 3000 amps 100,000 100,000 125,000
Since type A Robonics employ magnetic only breakers, their interrupting,
closing, and withstand ratings are the same value. Under fault
conditions, with its normal breaker closed, a Robonic is required to
withstand the energy let through of the normal service protective
device while the fault is being cleared. At the same time, should the
normal voltage fall below the voltage sensing relays selected value, 
and if the alternate source were available, the Robonic could transfer
before the normal service protective device cleared the fault.
This would require that the Robonic be capable of interrupting the
protective devices let through current. In addition, the Robonic could
be required to close in on a fault. Thus can be seen the need for
Robonics to have, interrupting, closing and withstand ratings.
The interrupting, closing and withstand ratings shown in Table 1 are
those for standard type A Robonics. For higher values, consideration
can be given to use of Robonics built with Mark 75, Tri-Pac or SCB
breakers.
Table 2  Maximum Upstream Circuit Protective Devices for
Type A Robonics, All Classes of Loads
Standard Robonic Maximum Upstream Maximum Upstream Fuse Rating
Continuous Breaker Frame Size
Rating (amperes) Class J or L Class K5 or R
30, 70, 100 EHB, FB, FB-P 100 100
150, 225 CA, JA, KA 225 225
400 DA, LB, LA-P 400 400
600 LA600 600 600
800 MA, MC, NB-P 800 800
1000, 1200 NB, NC 1200 ....
1400, 2000 PB, PB-P, PCC 2000 ....
Table 3  Maximum Upstream Circuit Protective Device for
Type A Robonics, 90% or Larger Motor Load
Standard Robonic Maximum Upstream Maximum Upstream Fuse Rating
Continuous Breaker Frame Size
Rating (amperes) Class J or L Class K5 or R
30, 70, 100 EHB,FB,HFB,FB-P 300 100
LA-P,c/w 400 LAP10
150, 225 CA,JA,KA,HKA,LA 400 22 5
HLA,LB,HLB,MA,NB
LA-P,NB-P c/w 1000
NB14 MC,NC
400 LA,HCA,LA-P,LB,MA 600 400
HMA,NB,HNB,NB-P
MC,HMC,NC,HNC
600 MA,HMA,MC,HMC 1200 600
NB,NC,HNC,NB-P
800 MA,HMA,NB,HNB, 1200 ....
NB-P
MC,HMC,NC,HNC
1000 NB,HNB,NC,HNC,PB-P 1200 ....
1200 NB,HNB,NC,HNC,PB-P 1200 ....
1400, 2000 PB,PB-P,PC 2000 ....
Automatic Control
Voltage Sensing Relays
Ratings  1.0 volt-ampere power consumption
Input Coil Voltage  120 volts at 50/60 hertz
Contact Rating  3.0 amperes resistive at 120 volts
Duty  continuous
Operating Temperature Ratings  -10°C to +55°C
Description
The device VS is an octual plug-in unit complete with solid-state
sensing and a DPDT relay enclosed in a dust-tight, yellow capsule.
The receptacles and plugs are designed to ensure a tight fit to reduce
the possibility of coming loose through vibrations.
The solid state sensing of the fixed model has been factory set for
pickup and dropout values of 104 volts Ac and 84 volts Ac respectively.
The adjustable model voltage sensor has a variable range of pickup,
92 volts to 140 volts Ac and dropout, 90 volts to 138 volts Ac with a
close differential of 2 volts.
The contacts being two pole double throw allows one set to be
incorporated in the control scheme and an additional set for external
connections if required.
Application
When used on the Robonic Automatic Transfer Switch as an under-
voltage sensing device, they have been designated as devices VS.
The standard Robonic Transfer Switch comes with one fixed voltage
sensor, VS1, for single phase application and three fixed voltage
sensors, VS1, VS2 and VS3, for three phase applications, all of
which monitor the normal power source only.
The single phase voltage sensor is connected to the normal control
transformer, NT, to monitor the normal source.
The three phase voltage sensors are connected to three smaller
transformers, VST, which are connected in a delta-Wye configuration
for use on all voltages, including 120/208 volts, none of which use the
system neutral.