Top
Contact Information
Web Site Search
Intercom Repair Request Form
Videos
Navigation
FREE Manuals and Installation Guides
NuTone IK15 & IK25 DoorCom Systems
NuTone Intercom Systems - Service & Repair
NuTone Intercom Problems by Model Number
NuTone Intercom Photo Gallery
Vintage NuTone Intercom Catalogs
Rebuilds & Repairs
NuTone Door Chimes
Donations
M&S Systems (Music & Sound Intercom)

NuTone Intercom Photo Gallery > NuTone 478 Apartment Entry Intercom Amplifier > NuTone model 478 amplifier with blown up SCR

NuTone model 478 amplifier with blown up SCR

Here you can see how dramtically an SCR can fail if it's overloaded.  The case of the SCR is cracked from the overload of a dead short on the wires to the electric door release.  

This type of damage can also happen if the incorrect type of door release is connected to the 478 amplifer.

If it is necessary to have a special type of door security lock, a relay can be install between the 478 amplifer and the door latch.