Honeywell LCBS Connect, Руководство по применению, Страница: 7 / 44

LCBS CONNECT SOLUTION
7 31-00118EFS—01
Depending on the geographical location of our customer's building and of an air to air heat pump, electric auxiliary heat
may be required. In northern United States, if a heat pump compressor is not protected with a compressor heater, the
compressor must be locked out to prevent damage to it and electric heat must be used to heat building space. The latter
can be expensive, thus we provide adjustable settings to attempt to help contractors and building owners avoid excessive
electricity use. The LCBS Controller has an adjustable outdoor air limit sensor that can lockout heat pump compressor if
outdoor air temperature falls below an adjustable level. Given this potential extraordinary expense, we've developed
several techniques to attempt to reduce the cost of operation of electric heat. Honeywell provides an option to operate
electric heat in a standard manner; this concentrates on traditional comfort. It's called the "comfort" mode. Look for this
as you configure your air to air heat pump; it's a selectable option. If the building owner can tell their employees, staff to
have a sweater ready on very cold days, Honeywell offers the "savings" mode. This automatically depresses the heating set
point and results in electric heat cycling less, maintaining a lower heating set point.
Droop, Comfort and Saving Heat Pump Mode
What is "droop?" Simply put, it's a temperature value that "droops" below standard occupied or unoccupied heating set
point. Heat pumps do a super job of heating as long as it's not too cold outdoors. As we've described a few times,
sometimes the pump just loses the battle to provide adequate heating. When this happens, the LCBS Connect control
system supplements the compressor and begins using "fossil fuel" heating, typically electric strip heaters. So, standard
heat pump cycle is designed to terminate heat pump usage below established outdoor air temperature where the
efficiency is less than electric or gas heat.
Here's a summary of the "Comfort" and "Savings" mode:
Discharge Air Temperature High Limit Control
While heating, it is possible that discharge air temperature may increase beyond an unacceptable limit. To avoid this, the
LCBS Connect controller features discharge air temperature high limit control. When discharge air temperature increases
above the discharge air high limit set point, the heating equipment is controlled to maintain the discharge air
temperature to the set point. Let's assume that the discharge air set point is 120°F. If the discharge air temperature
increases above 120°F then the heating equipment is cycled off. When it falls back below the limit minus the switching
differential, it will be allowed to cycle back on.
Please note: Your HVAC unit will feature a high limit heating control.
Ensure that the LCBS Connect setting is HIGHER than that of the unit being controlled.
Heating Summary
LCBS Connect controllers have a wide array of heating options. As with most functions, if you are
commissioning a simple single heat conventional system, the LCBS Controller will work "out of the box." It
will be designed to work at 68°F occupied setting and 62°F unoccupied setting. You will have access to
changing proportional band, integral gain, and derivative gain if you wish. It is HIGHLY RECOMMENDED that you
DON'T alter these parameters unless a Honeywell LCBS Connect support professional tells you to do so. You will need to
make some basic changes to the device if you are commissioning a heat pump. There are a number of options described
in this document that will allow you to alter basic heat pump operation; most are provided so that the heat pump operates
in an
efficient manner . It is recommended that you don't change preconfigured parameters.
COOLING, DEHUMIDIFICATION, ECONOMIZER CONTROL
Cooling Theory and Operation
There are two key operational objectives for cooling. First, we have an objective to keep building occupants comfortable
during assumed cooling seasons during periods when occupants occupy buildings. A close following objective is to keep
building assets cool and dehumidified enough so that no building damage occurs when it's very warm and humid
outdoors. LCBS Connect controllers need to protect cooling systems so they don't operate in an inefficient manner, on in
a manner where damage occurs to the cooling systems. Some typical examples to protect cooling equipment are
"COMFORT" MODE "SAVINGS" MODE
Depending on outdoor limits set, the compressor, the
compressor acting in unison with auxiliary heat, or auxiliary
heat operates to maintain heating setpoint. If "savings" mode is selected and if auxiliary heat is not
locked out, the heating sepoint is depressed by "x" degrees.
this minimimzes the use of auxiliary heat and avoids energy
cost.
COMMENTS. BENEFITS, SHORTCOMINGS
Comfort is our prevailing concern for our employees,
guests, and patrons. Pushes pump operation thus saves energy. the more
aggressive the "savings" setpoint is, the more likely that
building zones will become cold. take care to select
parameters properly.