Pumps Control - Carrier Touch Pilot Manual

7.5.2 - Reset
Reset. means. the. active. setpoint. is. modified. so. that. less.
machine capacity is required.
The.reset.source.can.be.provided.by.one.of.the.following:
• Return water temperature (heat exchanger delta T
gives.an.average.building.load).
• 4-20 mA reset signal (4-20 mA signal / external
temperature reading indicates the load trend).
• Space temperature reset (EMM option).
The. source. of. the. reset. can. be. configured. in. the. Reset.
Configuration.menu.(RESETCFG)..In.response.to.a.change.
in the delta T, or 4-20 mA reset signal reading, or space
temperature, the control point is reset to optimise unit
performance.
In response to a drop in the reset source, the cooling setpoint
is normally reset upwards in order to optimise unit
performance.
To set Cooling / Heating Reset Select
1..Navigate.to.the.Configuration.menu.
2. Select Reset Configuration (RESETCFG).
3. Set Cooling Reset Select [cr_sel] OR
4. Set Heating Reset Select [hr_sel].
Cooling Reset Select [cr_sel]
Heating Reset Select [hr_sel]
0 = none
1 = delta T
2 = 4-20mA control T
3 = Space Temp
The amount of reset is determined by linear interpolation
based on the following parameters:
• A reference at which reset is zero (delta T or 4-20 mA
signal.or.space.temp..–.no.reset.value).
• A reference at which reset is maximum (delta T or
4-20.mA.signal.or.space.temp..–.full.reset.value).
• The.maximum.reset.value.
Reset example in Cooling mode
10 Reset based on space temperature
3 Reset based on delta T
4 Reset based on analogue input
no reset selection
Legend:
A: Maximum reset value
B: Space temp. / delta T / 4-20 mA for no reset
C: Space temp. / delta T / 4-20 mA for full reset
D: Building load

7.6 - Pumps control

The unit can control one or two water pump(s) per heat
exchanger (one or two cooler pumps OR one condenser pump).
7.6.1 - Pump setting
The.pump.is.turned.on.when.the.option.is.configured.in.the.
Pump.Configuration.menu.(PUMPCONF).and.the.unit.is.in.
heating/cooling mode, depending on installation, or in delay
mode.. Since. the. minimum. value. for. delay. at. start-up. is. 1.
minute.(configurable.between.1.and.15.minutes),.the.pump.
will.run.for.at.least.one.minute.before.the.first.compressor.
starts.
Please note that in case of units with two pumps on one heat
exchanger, only one pump can be running at a time (this
option applies only to cooler pumps).
To set the cooler pump(s)
1..Navigate.to.the.Configuration.menu.
2. Select Pump Configuration (PUMPCONF).
3. Set Cooler Pumps Sequence [cpumpseq].
Cooler Pumps Sequence [clpumpseq]
0 = No Pump
1 = One Pump Only
2 = Two Pumps Auto
*Values between 2 and 4 can be selected only in case of dual pumps control.
To set the condenser pump(s)
1..Navigate.to.the.Configuration.menu.
2. Select Pump Configuration (PUMPCONF).
3. Set Condenser Pumps Sequence [hpumpseq] to "1".
Condenser Pumps Sequence [hpumpseq]
0 = No Pump
1 = One Pump Only
IMPORTANT: 61XWHZE units can control one or two
cooler pumps and only one condenser pump.
7.6.2 - Pump operation
The pump keeps running for 2 minutes after the unit goes to
the stopping mode. The pump is turned off if the unit is shut
down due to an alarm unless the fault is a freeze protection
error.
The pump can be started in particular operating conditions
when.freeze.protection.of.the.heat.exchanger.is.active..
If.the.pump.has.failed.and.another.pump.is.available,.the.
unit is stopped and started again with the second pump.
If.there.is.no.pump.available,.the.unit.shuts.down.
7.6.3 - Automatic pump selection (cooler pumps)
If.two.pumps.are.controlled.and.the.reversing.function.has.
been selected (PUMPCONF), the control balances the pump
20
run.time.to.match.the.configured.pump.changeover.delay.
5
If. this. delay. has. elapsed,. the. pump. reversing. function. is.
20
activated.during.the.next.time.when.there.is.no.compressor.
full reset
running in the system.
To set pump automatic rotation delay
1..Navigate.to.the.Configuration.menu.
2. Select Pump Configuration (PUMPCONF).
3. Set Pump Auto Rotation Delay [pump_del].
Pump Auto Rotation Delay [pump_del]
24 to 3000 h
3 = Pump#1 Manual
4 = Pump#2 Manual
48 h
25