Belimo ECON-ZIP-BASE - High Limit Changeover; Operational Modes

33
0
6/16 - Subject to change. © Belimo Aircontrols
(
USA
)
, Inc
.
ZIP E
co
n
o
miz
er
Method of O
p
eration
High Limit Changeover
(F
our poss
ibili
t
i
es
d
epen
di
n
g
on
i
nsta
ll
e
d
sensors
)
N
ote: Economizing is enabled based on one o
f
the
f
ollowing and becomes
active in Free
C
ooling and Integrated
C
ooling.
Sin
g
le Dry Bulb Chan
g
eover
• If only an OAT sensor is connected, it will be analyzed against the reference
Outdoor Air chan
g
eover temperature value
(
based on entered ZIP code
)
.
• IF OAT is 2°F below the reference value
THEN economizin
g
will be enabled.
• IF
O
AT i
s
abo
v
e
th
e
r
e
f
e
r
e
n
ce
v
a
l
ue
THEN
econom
i
z
i
ng w
ill
b
e
di
sa
bl
e
d.
Differential Dry Bulb Changeover
• Must have
O
AT and RAT sensors connected.
O
AT and RAT will be analyzed
a
gainst each other and the OAT will be analyzed against the reference
di
ff
erential temperature high limit (based on entered ZIP code).
• IF OAT is 2-8°F below the RAT (Value Climate Zone Dependent)
AND OAT is 2°F below the reference differential temp hi
g
h limit DTH
L
THEN
econom
i
z
i
n
g
w
ill
b
e ena
bl
e
d
.
• IF OAT is greater than or equal to 0-6°F below the RAT (Value Climate
Z
one
D
epen
d
ent
)
OR the OAT is
g
reater than the reference differential temp hi
g
h limit DTH
L
THEN
econom
i
z
i
ng w
ill
b
e
di
sa
bl
e
d.
S
ingle Enthalpy
C
hangeover
• Must have OAH (RH) and OAT sensors connected. Outdoor air enthalpy
(Outdoor Enth) will be calculated. They will be analyzed against the
reference values as follows
:
• IF Outdoor Enth is 2 btu/lb less than the reference enthalpy hi
g
h limit
(
default is 28 btu
/
lb – 2 btu
/
lb = 26 btu
/
lb
)
AND OAT is 2°F below the reference temperature hi
g
h limit ETHL
(
based
o
n entere
d
ZIP
co
d
e
)
THEN economizin
g
will be enabled.
• IF Outdoor Enth is
g
reater than reference enthalpy hi
g
h limit
(
default is 28
btu/lb)
OR OAT is
g
reater than the reference temperature hi
g
h limit ETHL
(
based
o
n entere
d
ZIP
co
d
e
)
THEN economizin
g
will be disabled
.
Differential Enthalpy Chan
g
eover
• Must have OAH, OAT, RAH and RAT sensors connected. Outdoor Air
Enthal
py
and Return Air Enthal
py
will be calculated.
• IF Outdoor Enth is 2.5 btu/lb less than Return Air Enth
AND Outdoor Enth is 2 btu/lb less than the reference differential enthal
py
h
i
g
h limit DEHL
(
30 btu/lb
)
AND OAT is 2°F below the reference differential temperature hi
g
h limit
DTHL (based on entered ZIP code)
THEN
econom
i
z
i
n
g
w
ill
b
e ena
bl
e
d
.
•
If Outdoor Air Enthalpy is 1 btu/lb less than Return Air Enthalpy
OR Outdoor Air Enthalpy is
g
reater than reference enthalpy hi
g
h limit
DEHL (30 btu
/
lb)
O
R
O
AT is greater than reference differential temperature high limit
(
based on entered ZIP code)
THEN economizing will be disabled
.
Operational Modes
F
ree Coolin
g
•
Outdoor air ambient conditions are analyzed by one of the 4 changeover
strate
g
ies above
(
Sin
g
le or Differential Dry Bulb; Sin
g
le or Differential
Enthalpy
)
and has been deemed suitable
f
or “
f
ree” coolin
g
.
•
Y1 is energized indicating a call for stage 1 cooling.
•
Y
2
i
s
d
e-energ
i
ze
d.
•
W1 is de-ener
g
ized.
•
G input could be energized or de-energized (occupied or unoccupied state).
•
C
ompressor 1 is off
2
.
•
Com
p
ressor 2 is off
2
.
•
Fan Speed could be energized (low speed, when OAT is below 50°F) or
de-energized (high speed)
f
or indoor
f
an
1
.
•
E
x
h
aust
F
an cou
ld
b
e runn
i
ng or not
b
ase
d
on %
d
amper open pos
i
t
i
o
n
1
.
•
Dam
p
er Pos out
p
ut is modulated between the res
p
ective current minimum
dam
p
er
p
osition set
p
oint and 100% o
p
en to attem
p
t to maintain SAT
setpoint (55°F). When
O
AT is at 55°F the damper will be fully open to
outside air. As outdoor air continues to rise above 55°F,
S
AT will rise with it.
I
ntegrated
C
ooling
•
O
utdoor air ambient conditions are analyzed by one of the four changeover
strategies above (Single or Differential Dry Bulb; Single or Differential
Enthalpy) and has been deemed suitable for “free” cooling.
•
Y1 is energized indicating a call for stage 1 cooling.
•
Y2 is energized indicating a call
f
or stage 2 cooling.
•
W
1
i
s
d
e-energ
i
ze
d
.
•
G input could be energized or de-energized (occupied or unoccupied state).
•
Com
p
ressor 1 is on
2
.
•
Compressor 2 is off
2
.
•
Fan Speed is de-ener
g
ized
(
indoor fan is operatin
g
on hi
g
h speed
)
1
.
•
E
x
h
aust
F
an
i
s o
n
1
.
•
Damper Pos output is
fi
xed at 100%
(f
ully open to outdoor air
)
.
No
te: Outdoor Damper must be fully open for 60 seconds before mechanical
coolin
g
will be enabled.