Install Instructions

43
Tech.Doc - 03/21 - Subject to change. © Belimo Aircontrols (USA), Inc.
Problem Possible Cause Action
There is No
Free Cooling
Display shows “SAT
sensor out of range
economizing disabled”
Sensor is returning a value that is out of the predetermined range. This disables the economizer functions and outdoor
air damper will return/remain at minimum position. This is a mandatory sensor and must be functional! Repair or replace.
Verify sensor value by disconnecting sensor leads from ZIP-ECON-BASE and measure resistance with Ohm meter across
sensor leads and compare to 10K type 2 Thermistor Table values to measured values to the value of a temperature
instrument. If values are signifi cantly different, replace sensor.
Display shows “SAT
sensor not detected
economizing disabled”
Sensor is not present/not detected. This disables the economizer functions and damper will return/remain at minimum
position. This is a mandatory sensor and must be functional! Repair or replace. Verify sensor value by disconnecting
sensor leads from ZIP-ECON-BASE and measure resistance with Ohm meter across sensor leads and compare to 10K
type 2 Thermistor Table value to measured value to the value of a temperature instrument. If value is close, determine if
there is any intermediate wiring. If so, check continuity. If all checks are good, attach sensor to ZIP-ECON-BASE and see
if it is detected. If not detected, try another 10K type 2 sensor. If still not detected, replace ZIP-ECON-BASE.
The ZIP Economizer is
in another operating
mode
Check Status screen for current operating mode or state. Please see sequence description for more information.
A Sensor is
Not Detected
or Out of
Range
OAT sensor Please see troubleshooting action under Problem "There is no Free Cooling".
SAT sensor Please see troubleshooting action under Problem "There is no Free Cooling".
OAH sensor
When operating in single enthalpy limit confi guration, Please see troubleshooting action under Problem "There is no Free
Cooling", otherwise see below.
OAH Sensor.
Display shows “OAH
sensor not detected
operation by diff temp”
Sensor previously detected is not present. Previously confi gured for differential enthalpy, now economizing will be based
on differential dry bulb using RAH sensor to monitor space humidity to ensure it is not getting too high. The valid range
for reading an OAH sensor for auto detection is DC 0.6 V (6%RH) to (100%RH) up to DC 11.0 V. Using a voltmeter set to
read AC input voltage at TH sensor terminal R, verify that there is AC 24 V +/- 20% (AC 19...29 V). If input voltage is not
with present, check continuity of wiring between ECON-ZIP-TH sensor and ECON-ZIP-BASE, If voltage is present, remove
wires from RH+ and RH- and measure across the two terminal using voltmeter set to DC. If DC output voltage is within
valid range above, check continuity of RH+ and RH- output wires between ECON-ZIP-TH sensor and ECON-ZIP-BASE.
If continuity OK, go to settings menu and submenu Devices 2. Verify that display for OAH is Auto or Installed. If Auto,
change it to Installed and see if Alarm disappears or a value OAH value is displayed in Monitor Live Conditions menu.
Also can try to Delete alarm and see if sensor is again auto detected.
OAH Sensor.
Display shows “RAH
sensor detected
but OAH sensor not
detected”
Sensor previously detected is not present. Previously confi gured for differential enthalpy, now economizing will be based
on differential dry bulb using RAH sensor to monitor space humidity to ensure it is not getting too high.
RAT Sensor.
Display shows “RAT
sensor not detected
operation by OAT dry
bulb"
Sensor previously detected is not present. Previously confi gured for differential dry bulb, now economizing will be based
on single OAT dry bulb. Verify sensor value by disconnection sensor leads from ZIP-ECON-BASE and measure resistance
with Ohm meter across sensor leads and compare to 10K type 2 Thermistor Table value to measured value to the value
of a temperature instrument. If value is close, determine if there is any intermediate wiring. If so, check continuity. If all
checks are good, attach sensor to ZIP-ECON-BASE and see if it is detected. If not detected, try another 10K type 2 sensor.
If still not detected, replace ZIP-ECON-BASE.
RAT Sensor.
Display shows “RAT
sensor not detected
operation by OAH
enthalpy”
Sensor previously detected is not present. Previously confi gured for differential enthalpy, now economizing will be based
on single enthalpy. Verify sensor value by disconnecting sensor leads from ZIP-ECON-BASE and measure resistance
with Ohm meter across sensor leads and compare to 10K type 2 Thermistor Table value to measured value to the value
of a temperature instrument. If value is close, determine if there is any intermediate wiring. If so, check continuity. If all
checks are good, attach sensor to ZIP-ECON-BASE and see if it is detected. If not detected, try another 10K type 2 sensor.
If still not detected, replace ZIP-ECON-BASE.
RAT Sensor.
Display shows “RAH
sensor detected but RAT
sensor not detected”
This confi guration is not allowed. You need an RAT sensor for differential enthalpy high limit changeover. Verify that RAT
sensor installed and correctly wired. Troubleshoot as above for RAT.
RAH Sensor.
Display shows “RAH
sensor out of range
operation OAH
enthalpy”
Sensor previously detected is not present. Previously confi gured for differential enthalpy, now economizing will be based
on single enthalpy. The valid range for reading an RAH sensor for auto detection is DC 0.6 V (6%RH) to (100%RH) up to
DC 11.0 V. Using a voltmeter set to read AC input voltage at TH sensor terminal R, verify that there is AC 24 V +/- 20%
(AC 19...29 V). If input voltage is not with in range, verify input voltage at ECON-ZIP-BASE terminals R and C, if also out of
range, troubleshoot RTU control circuit. If the input voltage is within range, remove wires from RH+ and RH- and measure
across the two terminal using voltmeter set to DC. If DC output voltage is not within valid range above, replace sensor. If
sensor was intentionally disconnected then go to: Alarm, Delete Alarms, select the alarm. When prompted to, press enter
to permanently delete, press OK.
ZIP Economizer
Troubleshooting