LCN 4840 Installation Instructions Manual - page 3
3
Closing Force Adjustment (see Figure 3)
3a To adjust
Closing Force, turn the spring adjustment
nut clockwise or counter-clockwise the required
number of turns to match the door width in
Tables 1 &
2. Maximum adjustment, 5 turns counterclockwise and
7 turns clockwise.
CAuTiON
Do not set door speed faster than chart recommends.
4
Closing Speed Adjustment (See Figure 3)
4a THE 4840 SERiES CLOSER HAS BEEN
REGuLATED PRiORTO SHiPMENT. If regulation
adjustments are needed use 3/32 Hex wrench
furnished, and refer below.
4b A “normal” closing time from 90° open position is 5 to
7 seconds, evenly divided between
Main Speed and
Latch Speed.
4c To slow
Main Speed of door, turn regulating screw
(nearest to arm) clockwise.
4d To slow
Latch Speed of door, turn regulating screw
(nearest to latch) clockwise.
4e Do not allow door to slam into frame.
5
Backcheck Adjustment
5a Backcheck slows the door swing as it approaches full
opening
(see Figure 3).
5b Increase the resistance of backcheck only if necessary
to prevent the door from striking a wall. To do this,
turn the regulating screw (nearest to hinge) clockwise
by quarter turns.
DO NOT uSE AN ABRuPT
BACKCHECK.
Table 1
Exterior Door
Maximum Door Width
Number of Turns
30”
0 Turns
36”
2 Turns C.W.
42”
7 Turns C.W.
Table 2
interior Door
Maximum Door Width
Number of Turns
34”
5 Turns C.C.W.
38”
0 Turns
48”
2 Turns C.W.
54”
7 Turns C.W.
FIGURE 3
.
LATCH SPEED
MAIN SPEED
BACKCHECK
SPRING
ADJUSTMENT NUT
INCREASE
FORCE
DECREASE
FORCE