Dwyer DH3 - Manual (Page 7)

7
SETTING SET POINTS AND ALARMS
The hot key provides direct access to the Set Point and Alarm MENU. The Set
Point and Alarm MENUS that are displayed are based upon the Control (CtrL) SUB
MENU.
SP/AL SP/AL SP/AL SP/AL SP/AL SP/AL
SP/AL SP/AL SP/AL SP/AL SP/AL SP/AL
SP/AL SP/AL SP/AL SP/AL
SP/AL SP/AL SP/AL SP/AL SP/AL SP/AL
SP/AL SP/AL SP/AL SP/AL
Visible when Visible when
Visible when Visible when
Visible when Visible when
mode = mode =
mode = mode =
mode = mode =
CONTROL MODE CONTROL MODE CONTROL MODE CONTROL MODE
CONTROL MODE CONTROL MODE
SET POINT ADJUSTMENT
Adjusting the DH
® 3 Set Points is quick and simple. Instead of setting a set point and dead-
band, simply adjust SP1H or SP2H for the desired relay turn on point, and then adjust SP1L
or SP2L for the desired relay turn off point.
PRESSURE PRESSURE
0 0
0 0
TIME TIME
0.2 0.2
0.4 0.4
0.6 0.6
0.8 0.8
1.0
(in. w.c.)
In the above graph, an instrument with a 1.0˝ range would have the SP1 relay turn on at
0.8˝ and off at 0.4˝.
SP1H sets the relay turn on point, and SP1L sets the relay turn off point.
The relays outputs normally function in the direct acting mode, which means the relays turn
on with an increase in pressure. SP1 may be configured to act as a reverse acting relay
(refer to the 1SP SUB MENU setting, page 15). When set for reverse acting,
SP1H sets the
relay turn OFF point, and SP1L sets the relay turn ON point. SP2 is always direct acting.
SP/AL SP/AL