Installation and Operation
DTR-51 & DTR-61 Ringdown Telephones
Page 11
Fuses
•
There are no replaceable fuses in the DTR.
•
The phone line fuse on the circuit board of all models is of the resettable
type and is not replaceable. If the fuse trips due to an external event it will
reset in a short period of time. The duration will depend on ambient
temperature and other factors. If the fuse trips repeatedly, check the
telephone system wiring. The fuse protects the Tip and Ring line from the
telephone system. It is usually powered at 48 volts DC and must not be
connected to 120VAC or 230VAC.
•
The Ring Detect Relay fuse is a 5 Ampere, fast blow fuse. It is potted to
prevent an exposed spark. If the fuse blows, the circuit board must be
replaced.
Operating the DTR
Lift the handset and the telephone will dial automatically. Adjust the handset
volume to a comfortable level with the volume control switches on the handset.
When the call is completed replace the handset in the cradle.
