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PAMM - A unique security feature
The Plant Associated Memory Module (PAMM), being
mounted on the cassette (for withdrawable units) is
independent of the withdrawable circuit breaker and M-PRO
unit. All stored settings and data will be retained even when
power is removed from the M-PRO unit. The PAMM will
automatically assume the protection characteristics previously
set, regardless of any substitution of either the original circuit
breaker or M-PRO unit whether inadvertent or deliberate. This
unique feature ensures that protective settings are always
securely associated with the circuit characteristics for which
they were chosen.
NOTE: PAMM / M-PRO systems are despatched with the
protections settings at minimum and all memory related
features reset (history of trips, operations counter etc.).
NOTE: For M-PRO’s with normal operation below or close to
20% of the breaker rating it is recommended that an auxiliary
power supply is fitted.
Protection Features
Most settings may be adjusted at any time as long as the M-
PRO is powered up. If there is insufficient primary current or
the breaker is open (assuming no auxiliary power supply) then
a test box or battery box is required. Factory settings (e.g.
breaker rating) and input settings may only be changed if the
breaker is open, all other settings may be changed at any
time.
Long Time (& Short Circuit) Curve Type and Speed
Current
Time
Operating time/current settings may be viewed on the LCD
screen. Five types of long time curve are available for
selection. 16 curve speeds are available for selection by the
user. The Inverse Short Circuit characteristic is automatically
set by selection of the long time curve and follows its
parameters except that the speed is 10 times faster
Long Time Pick Up
The pick-up value at which long time protection starts.
Adjustable between 40% I
n
- 100% I
n
in 1% steps.
(I
n
= Nominal current rating of circuit breaker).
Inverse Short Circuit Current
It is possible to select the current at which the inverse short
circuit protection will take over from the long time protection.
This current is adjustable in the following steps:
1.5, 2, 3, 4, 6, 8, 10 and 12 x Ir
Short Time Pick Up
It is possible to select the current level at which the short time
circuit protection will take over from the inverse time short
circuit protection. The current pick-up is adjustable in the
following steps:
1.5, 2, 3, 4, 6, 8, 10 and 12 x Ir
Short Time Delay
A short time circuit delay can be set on the M-PRO unit.
Adjustable
steps are as follows: Instantaneous to 1 sec in steps of 0.1
sec.
Time
Time
Time
Current
Current
Current
Current
Time
