1) Here is Diehl 880 instruction manual
2) Diehl 880 is 120V timer
-1000 Watt tungsten. Tungsten means incandescent light bulbs.
a) Your load does not exceed capacity > Timer is too lightweight to control 1500 toaster oven.
b) You need 120V line coming from breaker box with black Hot wire and white Neutral
c) You need 120V line going to Load that also has black and white wire
d) Test each black wire to ground to see which black wire is HOT
4) Deihl 880 sell sheet pdf
says 880 is available SPST (single pole single throw) -or- SPDT (single pole double throw).
-The difference is pole #4 on the timer
-If you are trying to turn one circuit off just as another circuit turns on, then you need the SPDT
-If you are turning one circuit on-and off, then the following instructions are for you
5) Wire clock
-There are 5 poles > look for markings 1-thru-5
-If no marking, then poles 1&2 are probably spaced apart from other poles
-Connect Hot and Neutral wires to poles 1&2 >> this powers clock motor, they go on either pole
-Pole 4 not used
6) Wire timer
-Poles 3&5 are timer circuits
-Connect Hot line to pole 3
-Connect black wire going to Load to pole 5
-Connect white wire from Load to Neutral