Pelco Manual C342M-PSA (11/98) 17
4.0 OPERATION
Refer to the manual for your control equipment for operating the pan/tilt unit.
If your enclosure has the heater blanket option, it is thermostatically controlled to
turn on at 40°F (4.44°C) and turn off at 60°F (15.56°C). The heater blanket allows
operation of the pan/tilt unit to -50°F (-45.56°C).
5.0 MAINTENANCE
If you need to remove the enclosure, protect the RediLINK™ connector area against
moisture, dust, dirt, etc. Failure to do so could result in a bad connection. Also,
damage to the pan/tilt unit or enclosure could occur when power is turned on.
The following servicing should be done every six months with average use.
1. Remove the PT780’s outer casing. (Refer to step 1 under Section 3.4, PAN
AND TILT STOP LIMIT ADJUSTMENTS.)
2. Inspect the gaskets around the cover, tilt shaft, and spindle for damage.
3. Refer to Figure 13. It shows the parts locations of the tilt assembly. Look for
similar orientations of parts when adjusting the pan assembly.
4. Check the backlash adjustment.
Backlash is the slack or binding in a pan and tilt base mount. Determine back-
lash by lifting the mount assembly, grasping the base, and wiggling it. There
should not be any play or binding between the gear (A) and worm drive (B).
Play or binding indicates a backlash problem.
• One backlash problem involves a worm and worm gear connection loose
enough to cause slipping or tight enough to cause binding.
• The second involves a too-loose or too-tight chain, usually causing symptoms
similar to the worm and worm gear problem—slipping or binding.
a. Verify that the worm drive (B) is fully seated in the worm gear (A). If it is not:
(1) Locate the worm-driven gear for either the pan or the tilt motor linkage.
Loosen the three hex screws (F) holding the worm in place, but leave
enough thread in place to hold the assembly on the mount.
(2) Using your thumbs, gently move the worm forward or pull the assembly
back from the worm gear to either tighten or loosen the gear spacing to
the worm gear. Move the base of the pan and tilt to check the adjust-
ment.
(3) If you get movement in the base, press a finger down in the middle of the
worm assembly. If you get no movement in the base, use your thumb
and forefinger to pull the worm assembly back until you get movement.
(4) When the spacing is correct, tighten the hex screws. Start with the middle
screw to ensure proper spacing.
(5) Remove the screw (C) in the gear train nut (D).
(6) Tighten the gear train nut to remove any play.

Figure 13. Pan/Tilt Adjustments

G
H