Carrier 30XW150-400 specifications Reset, Item Expansion Path Value Dmdc, DLS1, DLS2, Cur.S

	6
	5
F)	4
(deg		Cooling Reset
		Deg. Value,
Reset
	3	DGRC
				Current No Reset Value,
Degrees
					CRV1
	2
								Current Full Reset Value,
	1								CRV2
	0
	0	2	4	6	8	10	12	14	16	18	20
						mA Signal				a30-4482

Fig. 23 — 4 to 20 mA Temperature Reset

Demand Limit — Demand limit is a feature that allows the unit capacity to be limited during periods of peak energy usage. This allows the owner to keep energy costs down. There are three types of demand limiting that can be configured. The first type is through 2-step switch control, which will reduce the maximum capacity to 2 user configurable percentages. The second type is by 4 to 20 mA signal input which will reduce the maximum capacity linearly between 100% at a 4 mA input signal (no reduction) down to the user-configurable level at a 20 mA input signal. The third type uses the CCN Loadshed module and has the ability to limit the current operating capaci- ty to maximum and further reduce the capacity if required. De- mand limit control can be based on a calculated capacity level or by compressor current level.

NOTE: If using the compressor current level for demand limit, take into account the other power draws such as the condenser- fan motors when determining the limit value desired.

SWITCH CONTROLLED DEMAND LIMIT — The con- trol system is capable of demand limit based on a field-sup- plied switch for 1-step demand limit or 2 switches for 2-step demand limit. One-step demand limit is standard. The 2-step switch control of demand limiting requires the Energy Man- agement Module (EMM). Demand limit steps are controlled by two relay switch inputs field wired to TB5-5 and TB5-14 for Switch 1 and TB6-14 and TB6-15 for Switch 2.

For demand limit by switch control, closing the first de- mand limit contact will put the unit on the first demand limit level, either by capacity or compressor current. The unit will not exceed the percentage of capacity or compressor current entered as Demand Limit Switch 1 set point. Closing contacts on the second demand limit switch prevents the unit from ex- ceeding the demand limit entered as Demand Limit Switch 2 set point. The demand limit percent capacity or compressor current that is set to the lowest demand takes priority if both de- mand limit inputs are closed. If the demand limit percentage does not match unit operation, the unit will limit capacity or current to the closest step without exceeding the value.

To use demand limit, select the type of demand limiting to use by configuring the Demand Limit Select variable (De- mand Limit Type Select, DMDC) to Switch. Configure the Demand Limit set points based on the type selected.

Switch Controlled (Capacity Based) — If using 2-step de- mand limit control, an energy management module must be in- stalled. One-step demand limit control does not require the en- ergy management module. To configure Demand Limit for switch control, three parameters for 1-step switch control must be configured. For 2-step control, four 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 Set- point 2, DLS2), and Current Limit Select (Current Limit Se- lect, CUR.S). Current Limit Select must be set to NO.

To configure this option with the Touch Pilot™ display:

DISPLAY NAME	PATH	LINE NO.	VALUE
Demand Limit	Config→ USER	24	1 (Switch Control)
Type Select			Default = 0 (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	No
Select			Default = No

To configure this option with the Navigator™ display:

ITEM	ITEM EXPANSION	PATH	VALUE
DMDC	Demand Limit	Configuration→ RSET	SWITCH
	Select		Default = NONE
DLS1	Switch Limit	Setpoints→ MISC	Default = 100%
	Setpoint 1
DLS2	Switch Limit	Setpoints→ MISC	(Not required
			for 1-Step)
	Setpoint 2
			Default = 100%
CUR.S	Current Limit	Configuration→ OPTN	NO
	Select		Default: NO

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