©
2010 D
132
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04/10
4
of
12
2-STAGE DEMAND ----------------------------------------------------------------------------------
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A 2-stage demand is required in order for the 132 to provide additional flow. A 2-stage
demand is generated by applying a voltage between 24 and 240 V (ac) across the
2-Stage
Demand
terminals (3 and 4). Once voltage is applied, the
2-Stage Demand
light is turned
on. A 2-stage demand can come from an additional pressure differential switch, a tem-
perature differential device, or a setpoint control based on an outdoor air temperature.
Note:
The 2-stage demand device should provide an appropriate differential to prevent the
second stage pump from short cycling.
Section B2: 2-Stage
PUMP OPERATION ----------------------------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------------------------
The first stage pump contact closes whenever there is a pump demand and the 132 is not in WWSD. The second stage pump con-
tact closes whenever there is a pump demand, flow proof, 2-stage demand, and the 132 is not in WWSD.
If flow is not established by the first stage pump, the 132 turns off the first stage pump contact and turns on the second stage pump
contact. An alert contact is activated to indicate the failure. The second stage pump contact also turns off if a flow proof is not
obtained once the flow proof delay has expired.
There are two alert contacts (
Alert A and Alert B
) on the Pump Sequencer 132. These contacts are used to indicate either pump or
control failures. The alert contacts have two modes of operation. The mode of operation for the alert contacts is selected using the
Alert per Pump / Alert Levels
DIP switch. When an alert contact is activated, refer to the
Error Messages
section of this brochure to
determine the cause of the alert signal. To clear an alert, press the
Clear Alert
button.
When operating in the
Alert Levels
mode, the alert contacts are used to indicate the level of failure in the system.
ALERT A (Non-Critical) -----------------------------------------------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------------------------------------------
The
Alert A
contact closes when a non-critical failure occurs. Non-critical failures include: a single pump failure, a control error, an
outdoor sensor failure, or short cycling of the 2-stage demand. With these failures, it is still possible to establish flow in the system.
ALERT B (Critical) ------------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------------
The
Alert B
contact closes when a critical failure occurs. Critical failures include: the failure of both pumps, or a failure of the flow
proof device. With these failures, the control is no longer able to operate the pumps, and it is not possible to provide flow.
When operating in
Alert per Pump
mode, the alert contacts are related to the pump contacts on the control. The
Alert A
contact closes
anytime
Pump 1
fails, and the
Alert B
contact closes anytime
Pump 2
fails. The
Alert A
contact also closes to indicate an outdoor
sensor failure, a control error, a flow proof device failure, or if the 2-stage demand is short cycling.
Section C: Alert Operation
Section C1
Alert Levels
Section C2
Alert per Pump
Section C1: Alert Levels
Section C2: Alert per Pump
3
4
2-Stage
Demand
24 to 240 V (ac)
Содержание Pump Sequencer 132
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