Figure 9. Flow Chart of Setting Alarm Parameters.
Note 17: AH (High Alarm), determines at what temperature that is higher than
the set temperature the alarm relay will be activated. This setting applies to both
process and derivation alarms. The unit is in degree C or F. AH1 is for Relay 1
and AH2 for Relay 2. It can be set to any temperature that the controller is
capable to reading, or set to “off”. If a relay is set to process alarm, the value of
AH represents the absolute high alarm; the relay will be activated when PV >=
AH. If a relay is set to deviation alarm, the value of AH represents the
temperature deviation above the set value; the relay will be activated when
PV >= (SV+ AH).
Note 18: AL (Low Alarm), determines at what temperature that is lower than
the set temperature the alarm relay will be activated. This setting applies to both
process and derivation alarms. The unit is in degree C or F. It can be set to any
temperature that the controller is capable of reading, or set to “off”. If a relay is
set to process alarm, the value of AL represents the absolute low alarm; the relay
will be activated when PV <= AL. If a relay is set to deviation alarm, the value of
AL represents the temperature deviation below the set value; the relay will be
activated when PV <= (SV- AL).
Tip 1: In Process Alarm Mode, AL should always be less than AH (AL1 < AH1,
AL2 < AH2), otherwise, the alarm relay will stay activated all the time.
Tip 2: A relay can be set to work for process/deviation high alarm only (i.e., set
AL = off), for low alarm only (i.e., set AH = off), or for both high and low alarm.
Tip 3: Deviation alarm settings are not valid for Boiling Mode (on DSPR120 or
DSPR300) where there is no set temperature.
Note 19: HY (Hysteresis Band), determines the hysteresis band between
temperature of activating and deactivating alarms. It is also called differential
band by some manufacturer. The unit is degree F or C. For example, Relay 1 is
set as a non-latching process alarm with relays settings RL1 = Pr, Lgc1 = RL_C,
LAt1 = N, AH1 = 200, AL1 = 100 and HY = 3 (temperature unit is F). For the
high limit alarm, when the process temperature is greater and equal to 200˚F,
the relay will pull in; and when process temperature is less than 197˚F, relay will
drop off. For the low limit alarm, relay will pull in when process temperature is
less than 100˚F; and the relay will drop off when process temperature is greater
or equal to 103˚F.
Note 20: AP (Alarm Pulse), determines the time duration of which a relay stays
activated. The unit is second. Pulse length can be set from 1 to 100 seconds.
This setting is only valid when the Relay Latching Mode is set to Pulsing, i.e.,
LAt = P.
8. Application Examples
8.1 Timer operation example
The timer can be used for several ways to help managing mashing or boiling
process.
1) Use it to automatically control the boiling time (boiling mode).
Set the parameter as following
tF=on, btSP=210, tdIr=dn, bEO=OFF, bt=1:30,
The timer will start to count when temperature reaches 210 degrees. The timer
will count down from 1:30, when time out, the controller will stop heating, beeps,
and flash “End”.
2) Use the timer as a regular timer (boiling mode).
Set btSP below the ambient temperature so that timer is available, set bt to a
very long time so that it will not end before operator decide to end the boil. The
counting direction should be up. Use the reset button (rSt) to reset the timer at
any time
tF=on, btSP=50, tdIr=up, bEO=on, bt=60:00.
3) Use the timer as a regular timer (mashing mode).
Set tSP below the ambient temperature so that timer is available, set t to a very
long time so that it will not end before operator decide to end the mash. The
counting direction should be up. Use the reset button (rSt) to reset the timer at
any time
tF=on, tSP=50, tdIr=up, EO=on, t=60:00.
4) Use EZboil as a manual regulator (similar to DSPR1)
To use it as manual regulator with temperature reading, please set it to boiling
mode. Disable timer, and set boiling acceleration set temperature below ambient
temperature (or just zero).
Mode=boiling, tF=off, bAST=0
9. Wiring Examples
Example 1. Here are two wiring diagrams of how to connect a DC triggered AC
SSR with this power regulator.
