Rockwell Automation 825 Smart Motor Manager User Manual - Manual (Page 30)

2-10 Equipment Description
Publication 825-UM001B-EN-P January 2001
Main Current Transformers for the Motor Circuit
When the Cat. No. 825-M Control and Protection Unit is used as a secondary relay with Cat.
Nos. 825-MCM2 and 825-MCM20, the following specifications apply:
Table 2.G Main Current Transformer Ratings
➊ Designation according to IEC 60044 part 2:
With starting current 10 ,
e
: class 5 P 20
The current transformer error in addition to the basic unit error
➋ 2.5 A with Cat. No. 825-MCM2, 20 A with Cat. No. 825-MCM20
Minimum nominal operating voltage Nominal operating voltage of motor
Minimum rated primary current ,
1n Nominal operating current of motor
Rated secondary current 1 A or 5 A
Class and nominal
overcurrent factor
5 P 10 ext. 120% ➊
Power rating
According to power consumption in leads
and measuring circuits
Rated frequency 50/60 Hz
Burden:
825-M +
825-MCM2
825-M +
825-MCM20
Power consumption at max. rated current ➋ 0.1 VA/phase 0.4 VA/phase
Continuous thermal current 3 A 24 A
Thermal current, 1 s duration 250 A 600A
Frequency of input current 50/60 Hz 50/60 Hz
General Notes on 825-MCM…
No-load
An open-circuit secondary is permitted, as the burden is
installed in the detection module
5 Total measurement error (percentage):
±5% within range up to rated nominal overcurrent (10X)
±1% at rated nominal primary current
P For protection purposes
10 Rated nominal overcurrent factor: 10X rated nominal primary current
ext.
120% Extended rated thermal current: 120% of rated nominal primary current (if ,
e
motor > 87% of
rated nominal transformer current)