Carrier 30XW150-400 Touch Pilot Display Navigator Display, Dmdc Switch, DSL1, DSL2, Cur.F, Dmmx

In the following example, 2-step demand limit based on capacity is desired with the first switch closure limiting the capacity to 60%. The second switch closure is to limit the capacity to 40%. Demand Limit Switch 1 is 60% and Demand Limit Switch 2 is 40%.

TOUCH PILOT DISPLAY		NAVIGATOR DISPLAY
Display Name	Value	Item	Value
Demand Limit Type Select	1	DMDC	SWITCH
Switch Limit Setpoint 1	60%	DSL1	60%
Switch Limit Setpoint 2	40%	DSL2	40%
Current Limit Select	No	CUR.S	NO

Switch Controlled (Current Based) — If using 2-step de- mand limit control, an energy management module must be installed. One-step demand limit control does not require the energy management module. Four parameters for 1-step switch control must be configured. For 2-step control, five parameters must be configured. The parameters are: the type of Demand Limit Selection (Demand Limit Type Select, DMDC), the setting for Switch Limit Set Point 1 (Switch Limit Setpoint 1, DLS1), the setting for Switch Limit Set Point 2 (Switch Limit Setpoint 2, DLS2), the Current Limit Select (Current Limit Select, CUR.S), and the Compressor Current limit at 100% signal, (Current Limit at 100%, CUR.F).

To configure this option with the Touch Pilot display:

DISPLAY NAME			PATH		LINE		VALUE
					NO.
Demand Limit		Config→ USER				1 (Switch Control)
					24	Default = 0
Type Select
						(None)
Switch Limit		Setpoints→ SETPOINT			33	Default = 100%
Setpoint 1
Switch Limit		Setpoints→ SETPOINT				(Not required
					34	for 1-Step)
Setpoint 2
						Default = 100%
Current Limit		Config→ USER			30	Yes
Select						Default = No
Current Limit		Config→ USER			31	Default =
at 100%						2000.0 Amps
To configure this option with the Navigator™ display:
ITEM	ITEM EXPANSION			PATH			VALUE
DMDC	Demand Limit			Configuration→ RSET			SWITCH
							Default =
	Select
							NONE
DSL1	Switch Limit			Setpoints→ MISC			Default =
	Setpoint 1						100%
							(Not required
DSL2	Switch Limit			Setpoints→ MISC			for 1-Step)
	Setpoint 2						Default =
							100%
CUR.S	Current Limit			Configuration→ OPTN			NO
	Select						Default: NO
CUR.F	Current Limit			Configuration→ OPTN			Default =
	at 100%						2000

EXTERNALLY POWERED (4 to 20 mA) CAPACITY BASED DEMAND LIMIT — The energy management module is required for 4 to 20 mA demand limit control. An externally powered 4 to 20 mA signal must be connected to TB6-1 and TB6-2. To configure demand limit for 4 to 20 mA control based on unit capacity, four parameters must be config- ured. The parameters are: the type of Demand Limit Selection (Demand Limit Type Select, DMDC), the current at which 100% capacity limit takes place (mA For 100% Demand Limit, DMMX), the current at which 0% capacity limit takes place (mA For 0% Demand Limit, DMZE), and the Current Limit Selection (Current Limit Select, CUR.S).

CAUTION

Care should be taken when interfacing with other control systems due to possible power supply differences such as a full wave bridge versus a half wave rectification. Connec- tion of control devices with different power supplies may result in permanent damage. ComfortLink™ controls incorporate power supplies with half wave rectification. A signal isolation device should be utilized if the signal gen- erator incorporates a full wave bridge rectifier.

To configure this option with the Touch Pilot™ display:

DISPLAY NAME	PATH	LINE NO.	VALUE
Demand Limit	Config→ USER	24	2 (4-20mA Control)
Type Select			Default = 0 (None)
mA For 100%	Config→ USER	28	Default = 0.0 mA
Demand Limit
mA For 0%	Config→ USER	29	Default = 10.0 mA
Demand Limit
Current Limit	Config→ USER	30	No
Select			Default = No

To configure this option with the Navigator display:

ITEM	ITEM EXPANSION	PATH	VALUE
DMDC	Demand Limit	Configuration→ RSET	4-20MA INPUT
	Select		Default = NONE
DMMX	mA for 100%	Configuration→ RSET	Default =
	Demand Lim		0.0 mA
DMZE	mA for 0%	Configuration→ RSET	Default =
	Demand Limit		10.0 mA
CUR.S	Current Limit	Configuration→ OPTN	NO
	Select		Default: NO

In the following example, a 4 mA signal is Demand Limit 100% and a 20 mA Demand Limit signal is 0%. The 4 to 20 mA signal is connected to TB6-1 and TB6-2. The demand limit is a linear interpolation between the two values entered. In Fig. 24, if the machine receives a 12 mA signal, the machine controls will limit the capacity to 50%.

EXTERNALLY POWERED (4 to 20 mA) CURRENT BASED DEMAND LIMIT — The energy management module is required for 4 to 20 mA demand limit control. An externally powered 4 to 20 mA signal must be connected to TB6-1 and TB6-2. To configure demand limit for 4 to 20 mA control based on compressor current, five parameters must be configured. The parameters are: the type of Demand Limit Selection (Demand Limit Type Select, DMDC), the current at which 100% capacity limit takes place (mA For 100% Demand Limit, DMMX), the current at which 0% capacity limit takes place (mA For 0% Demand Limit, DMZE), the Current Limit Selection (Current Limit Select, CUR.S), and the Compressor Current limit at 100% signal (Current Limit at 100%, CUR.F).

To configure this option with the Touch Pilot display:

DISPLAY NAME	PATH	LINE NO.	VALUE
Demand Limit	Config→ USER	24	2 (4-20mA Control)
Type Select			Default = 0 (None)
mA For 100%	Config→ USER	28	Default = 0.0 mA
Demand Limit
mA For 0%	Config→ USER	29	Default = 10.0 mA
Demand Limit
Current Limit	Config→ USER	30	Yes
Select			Default = No
Current Limit	Config→ USER	31	Default = 2000.0 Amps
at 100%

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