User Guide

MENU ITEM PURPOSE
SEQUENCE TYPE
s Select the method of which the boilers will turn on and
off. Choose between SERIES, PARALLEL, or SMART.
SERIES sequencing allows each boiler to reach full input
before bringing on the next boiler in sequence. PARALLEL
sequencing uses a limiter, called BASERATE HIGH, to limit
the firing rate before adding additional boilers. SMART
sequencing (factory default setting) uses a low firing rate
setting, called BASERATE LOW, to keep boilers at a low firing
rate, bringing on additional boilers at reduced rate until all
boilers are on if necessary. Boilers are then allowed to modulate
together as high as necessary to meet demand.
BASERATE HIGH
s This sets highest modulation rate before turning on the next
boiler.
s This is read-only if in SMART mode.
BASERATE LOW
s This sets rate that the next boiler in sequence is going to turn
on when called.
s This is only visible if the Sequence Type is selected as SMART.
LEAD BOILER
ROTATE
s Choose how to rotate the boiler sequencing. Choose either
OFF, BY BOILER ID, TOTAL HOURS, or INCREMENTAL
HOURS. Firing sequence is changed every rotation period
(ROTATE FREQ – see setting explanation below).
s OFF — Master boiler is always the first to fire. Others fire in
the order of their network ID.
s BY BOILER ID — Lead boiler toggles in the sequence of net-
work ID numbers (changes from boiler number 1 to number
2, then boiler number 2 to number 3, etc.).
s TOTAL HOURS — The boiler with the most lifetime oper-
ating hours is moved to the last in the firing sequence. The
boiler with the least lifetime operating hours is made first in
the sequence. Others are ordered by their respective lifetime
operating hours.
s INCREMENTAL HOURS — Firing sequence is based on
the operating time during the previous rotation period.
The boiler with the least operating time is started first; the
boiler with the most operating time is started last; all others
are started in order of their operating time.
ROTATE FREQ
s Recalculates the boiler order every ## days based on LEAD
BOILER ROTATE setting.
FORCE LEAD
ROTATE
s Select YES or NO. When the rotation frequency timer expires
and the new order is calculated, this forces off the boiler low-
est in the sequence. Then the boiler highest in the sequence
fires to replace it.
Current Order
s Shows the current firing order of the boilers on the network.
s This list updates based on how many boilers are detected and
the order of sequence based on the above settings.
s Sequence is shown as left-most boiler is first to turn on. Right-
most boilers are the first to turn off.
Figure 25 Evergreen
®
NETWORK SETTINGS menu (see Figure 22, page 46 to access CONTRACTOR menu)
Part number 550-100-193/0817
– 49 –
®
CONDENSING GAS BOILER — 70/110/155 Advanced Manual
ROTATION AND SEQUENCE
Boiler Model, Altitude and Fuel Type are criti-
cal settings.
Failure to set correctly could result in
severe personal injury, death or substantial property
damage.
1. Access contractor menus by pressing and holding the UP and
DOWN arrow keys at the same time for 7 seconds.
2. See Figure 22, page 46 for the screen sequences up to the
CONTRACTOR menu.
Screens shown above are typical only.
Actual screens depend on control
settings chosen.