Marshalling box in a transformer

can someone please elaborate about marshalling box in a transformer?
it is having RTD(or thermocouples) for measurement of oil and winding temperatue only or something else also? Posted in: #Coffee Room

please reply it..

Marshalling box is a kind of panel which is situated next to transformer, it contains OTI or oil temperature indicator, WTI or winding temperature indicator, heater switch, pump control switch, fan control switch, mcb and contractors.

Let me know, if other queries rises in your mind.

what is heater switch?
for what heater is used
and tell me some also about contractors?

heater switch is used to dry heat process in which the moisture that is trapped inside the transformer is eliminated and contractors are terminal points in the panel box....

thanks marshalling box is now clear
will you please also tell about oil surge relay in the transformer?

[FONT="]It has only one float & operates when oil surges reach and strike the float of OSR. It is used with OLTC for detection of any damage or fault inside the tap changer and prevents tap changer from damages in case of low oil level in OLTC tank.[/FONT]

What about the connection in the marshalling box ? How WTI and OTI connected and mcb is it used for tripping purpose in case and of OTI and WTI heats up?