Demand; Auxiliary Delay Timers - Watts AERCO Edge [ii] Operation Manual

Edge [ii] Controller Operation Manual
SECTION 7 – UNIT STATUS

7.1.1 Demand

1. Upon a demand for heat, the Demand rectangle turns green, and, if the sequence has a
delay timer, those timers display appropriate values.
Figure 7.1.1: Ignition Sequence Step 1 – Demand
2. Upon expiration of the internal 4 second IGST Demand delay and the unit progresses to the
Auxiliary Delay sequence.

7.1.2 Auxiliary Delay Timers

1. Upon expiration of the internal 4 second IGST Demand delay, On Delay Timer starts,
followed by Auxiliary Delay Timer (if any). In both cases, the displays the count down.
Figure 7.1.2: Ignition Sequence Step 2 – Auxiliary Delay
2. When the On Delay Timer and all the interlock switches are closed, the Auxiliary Delay
rectangle turns green and the unit progresses to the Purging sequence.
•
If the interlock switches are closed and On Delay time has expired, the Auxiliary
Delay rectangle immediately changes to green, allowing for the purge cycle to begin.
•
If the any of the interlock switches are not closed when the auxiliary timer expires, the
Auxiliary Delay rectangle turns red and the correspond interlock fault is displayed.
•
OMM-139_E 8/25/2020
Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST
Page 169 of 196