Overvoltage Protection
If the
PS-7
regulator section should fail or one of the pass tran-
sistors should short, the unit will automatically shut down. If the
DC output voltage should soar above 16 VDC, an SCR crowbar
clamps the output to ground to protect the load and open the pri-
mary fuse.
This fuse should b e replaced with another of the same
type and rating after determining the cause of the overload.
Line Voltage Programming
The PS-7 comes factory set for 120 VAC 50-60 Hz operation. To
change the primary input range, simply remove the four screws
holding the programming plate. Refer to Figure 2. As an example,
suppose the line voltage measured 200 VAC. Remove the plate
and slide the voltage switch to 200/240. Then slide the HI/LO
switch to LO. Rotate the plate until 200 shows up in the window
and the LO switch fits through its locator hole. Reinstall the four
screws. If 200 or 240 VAC operation is desired, he
sure to replace
the fuse with a
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amperc type M TH fuse.
100
120
-lO% 50-60 Hz
Hi Lo
200 240 Range:108-132vac
Hi Lo
-lO% 50-60 Hz
Range:90-110vac
100 120 -l0% 50-60 Hz
Hi Lo 200
240
Range:216-264vac
100 120 -lO% 50-60Hz
Hi Lo 200
240
Range:180-220vac
Fig. 2-PS-7 Line Voltage Programming
1 0 - 8 - 7 9
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