Thus excessive ammonia injection to boiler flue gas affects insulation resistance of ESP electrodes?

[kadaffi_01]

I have trouble in one of our Boiler ESP. Every time after boiler & ESP maintenance we have issue starting up the ESP due to Low insulation (IR) resistance of the electrodes. We have checked the HV insulators and the transformer they are in good condition but still IR value is lower than normal criteria. My observation during running the boiler is that the ammonia injection system was operated manually, and i suspected that too much ammonia was injected causing Flue Gas to be more conductive thus low IR happened, is my assumption correct? thus anybody have the same issue? thanks in advance..