12-19

Safety Isolation System

ElectroGuard

Wire Length Considerations/Ordering Instructions

The total wire length for the 5 RLS to be wired to the Control

Module will be: 100ft + 400ft + 200ft + 600ft + 1,000ft = 2,300ft

Per the table entitled Total Wire Length for Remote Lockout Stations on

page 12-18, the maximum allowable wire length for 14AWG wire is

4,600ft for the RLS to be wired to the Control Module. This portion

of the installation will be within the maximum wire length permitted.

Next, we need to check the wire length calculation for the RLS to be

wired to the Expansion Module.

For RLS # 6: wire length = 1000ft x 2 = 200ft

For RLS # 7: wire length = 850ft x 2 = 1700ft

For RLS # 8: wire length = 750ft x 2 = 1500ft

The total wire length for the 3 RLS to be wired to the Expansion

Module will be: 2000ft + 1700ft + 1500ft = 5,200ft

Per the table entitled Total Wire Length for Expansion Modules on page

12-18, the maximum allowable wire length for 14AWG wire is

40,000ft for the RLS to be wired to the Expansion Module. This

portion of the installation will also be within the maximum wire

length permitted.

Ordering Instructions

1. Determine the Catalogue Number of the Safety Isolation System

based on the rating of the load(s) to which it will be connected as

follows:

If the Safety Isolation System is connected to a single motor load,

the horsepower or kilowatt rating of the system should be

determined as follows:

a. Select the Safety Isolation System that meets or exceeds the

horsepower or kilowatt rating of the load at the required

voltage and frequency.

If the Safety Isolation System is connected to two or more

motors or one or more motors in combination with other loads,

the horsepower or kilowatt rating of the system should be

determined as follows:

a. Identify the types of loads (i.e. motor, resistive) and the values

of the currents of each of the loads (i.e. steady-state current

for resistive loads, full-load and locked-rotor currents for

motor loads) to be connected to the Safety Isolation System.

b. Sum the full-load currents of all the motor loads to be

connected to the Safety Isolation System. To this value add

the current values of all resistive loads to be connected to

the Safety Isolation System. This value is the “combined

load full-load current.”

c. Find the horsepower or kilowatt rating of a single motor with

a full-load current value greater than or equal to the

“combined load full-load current” value determined in Step

“b”.

d. Select the Safety Isolation System that meets or exceeds this

horsepower or kilowatt rating at the required voltage and

frequency.

e. Sum the locked-rotor currents of all the motor loads to be

connected to the Safety Isolation System. To this value add

the current values of all resistive loads to be connected to

the Safety Isolation System. This value is the “combined

load locked-rotor current”.

f. Find the horsepower or kilowatt rating of a single motor with

a locked-rotor current value greater than or equal to the

“combined load locked-rotor current” value determined in

Step “e”.

g. Select the Safety Isolation System that meets or exceeds this

horsepower or kilowatt rating at the required voltage and

frequency.

h. Compare the ratings of the Safety Isolation Systems selected

in Steps “d” and “g”. Select the larger of the two systems for

your application.

2. Determine how many Remote Lockout Stations are required for

the application.

3. Determine how many Expansion Modules (if any) are required

for the application.

4. Pick suitable enclosure type(s) for the Safety Isolation System

Power Panel, Remote Lockout Stations and enclosed modules

(e.g., Expansion Modules, Pneumatic Isolation Module).

5. Determine what, if any, factory installed options are required for

the application (e.g. Pneumatic Isolation, Status Communication

to remote PLC, metering).