PMA-Relay S 3PH
from 60A to 210A
Trouble shooting
27
13.
Trouble shooting
Small problems sometimes can be solved locally with the help of the below tab of
trouble shooting. If you don’t succeed, contact us or your nearest distributor.
Symptom
Indication on front
unit
Possible reasons
of the symptom
Actions
Load current
doesn’t flow
Green LED (ON)
light OFF
• No Auxiliary Voltage
• No input signal
• Reversed polarities of input
signal
• Give auxiliary voltage supply
(See Connection Diagram)
• Provide to give input signal
• Reverse the input signal polarity
Green LED (ON)
light ON
• Fuse failure
• Load connection interruption
• Load failure: The yellow led
(HB) is light on (with HB option)
• Thyristor fault: The red led (SC)
is light on (with HB option)
• Change the fuse
• Check the wiring
• Check the load
• Change the thyristor module
Load current
flow also
without input
signal
Red LED (SC)
light ON
• Wrong wiring
• SCR short circuit
• Check the wiring
• Change the thyristor module
Current flows at
nominal value
but Yellow
LED (HB/SC) is
light on
Yellow LED (HB)
light ON
or
Red LED (SC)
light ON
• HB circuit not tuned
• Current transformers
not properly wired
• Make HB calibration procedure
• Check current transformers
wiring
Thyristor unit
doesn’t
work properly
• Auxiliary voltage supply out of
limits
• Wrong input signal selection
• Wrong input signal calibration
(out of range)
• Verify the auxiliary voltage supply
• Control input signal setting
• Check input setting
