Install Room End Switch; Optional Electrical Connections - ECR International Utica Boilers MAH-100 Installation, Operation & Maintenance Manual

8.6 Install Room End Switch

Install room end switch on inside wall. Do not install where it
will be influenced by drafts, hot or cold water pipes, lighting
fixtures, television, sun rays or near a fireplace.
Dry contact only - do not apply 24 volts between 6 and 7.
A. Connect Room End Switch
• turn power off to boiler;
• access terminal block M2;
• connect room end switch to terminals 6(R)-7(W)-
8(C); Do not apply dry voltage between 2 terminals.
Dry contact only.
• turn boiler power on;
• verify room end switch operates per end switch
manufacturer instructions.
NOTE: maximum load allowed is 10 mA
Dry contact end switches from various manufacturers can be
attached to boiler control PCB.

8.7 Optional Electrical Connections

A. 1K Ohm (1K Ω) Outdoor Temperature Sensor
To connect this accessory, see figure 8-5, terminals 4-5, and
instructions supplied with
B. Setting "Kt" Climate Curve
Boiler automatically recognizes OAS sensor when wired to M2
1.
terminal block. Display changes to show current default "Kt"
value (80). Note display value.
When operating in CH mode, boiler setpoint is determined
2.
by the Kt value selected and actual outside air temperature.
Refer to applicable °F (or °C) chart, (pg. 30) for setpoint
information.
• Select Kt range which will satisfy the desired boiler delivery
temperature based on outdoor temperature range expected
for your location. For example: if you need 176°F water
when the outside temperature is 20°F and colder, select 35
for your Kt setting.
• To change"default" Kt value on boiler control use
CH Heating buttons.
• Restrict the upper limit of the Kt curve by using Parameter
P16 to set the maximum boiler water temperature. P16
Default is 176°F.
When OAS is installed, pressing
3.
longer display boiler CH setpoint temperature. It now displays
the Kt value which can range from 10 to 90.
When scrolling has stopped, boiler will automatically "SAVE"
4.
value as new Kt default value and automatically return to CH
mode when no Kt adjustment activity is sensed. Kt values
can be changed in +/- 1 point increments.
To return, to verify or change current Kt "default value,
5.
depress one of the CH setpoint adjustment buttons (once),
or , while in any heating or standby mode. Adjust Kt
value to obtain desired comfort level.
8 - ELECTRICAL CONNECTIONS
1K Ω
sensor.
or buttons will no
FIGURE 8-4 End Switch Connections
FIGURE 8-5 Outdoor Sensor Connections
1K Ω
or
Sensors used for this boiler are proprietary to
Note
the manufacturer. Use of after market sensors
will diminish boiler performance.
43
A
Room End
Switch
W
R
240013354 REV A [07/01/2021]