AERCO BMS 168 - Manual (Page 34)

4.3.8 FIELD ADJ
The FIELD ADJ key LED should be lit to
indicate that the BMS is already in the Field
Adjust Mode. Pressing and releasing this
key when already in the Field Adjust Mode
will cause the BMS to exit the Field Adjust
Mode and switch the BMS to the Normal
(Read-Only) Mode.
4.3.9 SET POINT
Pressing and releasing this key allows you
to view or change the indoor setpoint
temperature. This function is only used
when an indoor air temperature sensor is
connected to the BMS. If used, the input
can be provided by a resistive type sensor,
or a 4-to-20 mA input.
4.3.10 PROP BAND
Pressing this key displays the indoor air
proportional bandwidth. This bandwidth is a
variable used in an equation that solves for
the proper offset of supply water
temperature based on an indoor air
temperature. Normally, the display will read
INDOOR PROP BAND 00.0°F/°F.
AERCO presets the proportional bandwidth
to 00.00°F/°F. It should NOT be readjusted
unless your system has an indoor air
temperature sensor and is operating in the
Indoor Setpoint mode. If the indoor
temperature feature is not being used,
PROP BAND MUST be set to 00.00°F/°F or
the BMS will not run the boiler plant.
4.3.11 OFFSET
The OFFSET key is used to enable and set
up an Offset Schedule for the header supply
temperature. The schedule can be set up
for a 7-day period.
Pressing and releasing this key once will
display OFFSET ENABLE followed by OFF
or ON (Default is OFF). If an Offset
Schedule will be used, toggle the display to
ON using the ▲ or ▼ arrow key.
Normally, if an Offset Schedule is used, it is
controlled automatically using the set-up
procedures described in paragraph 4.3.12.
However, if desired, the header offset can
be controlled manually by connecting a
switch across the SET BACK wiring
terminals (see para. 3.8). If a manual offset
is used, refer to paragraph 4.3.13
IMPORTANT
Prior to setting up an automatic
Reset Schedule (para. 4.3.12) or
manual Set Back (para. 4.3.13),
refer to the paragraph 4.3.4 to
determine which Day of the Week
has been set as Day 1. AERCO
presets Day 1 of the week as
Sunday. However, any day of the
week can be specified as Day 1 by
performing the steps outlined in
paragraph 4.3.4.
4.3.12 Setting Up A Reset Schedule
The basic steps for setting up an automatic
Reset Schedule consist of first selecting the
temperature offset and then entering the
start and stop times for which the offset will
be in effect. Keep in mind that the BMS
uses a 24-hour clock (00:00 to 23:59).
In the following example, for Day 1, we want
to offset the setpoint temperature by -15°F
starting at 12:30 am (00:30) and return it to
the normal setpoint at 8:15 am (08:15).
Proceed as follows:
1. Press OFFSET key once and toggle the
display to OFFSET ENABLE ON.
2. Press key a second time. OFFSET
TEMP DAY 1 Æ is displayed prompting
entry of the offset temperature. Set the
offset temperature to -15 using the ▲
and ▼ arrow keys.
3. Press key a third time. OFFSET ON
TIME DAY 1 Æ 0: 0 is displayed
prompting Hours to be entered for the
start time. Set the Hours to zero
(midnight) using the
▲ and ▼ arrow keys.
4. Press key a fourth time. OFFSET ON
TIME DAY 1: 0 Æ 0 is displayed,
prompting Minutes to be entered for the
start time. Set the Minutes to 30 using
the ▲ and ▼ arrow keys.
4-8