Vcm, vcm-x & vcb-x controllers, Vcb-x controllers vcb-x staging delay setpoints, Smts ii technical guide 58 – Orion System System Manager TS II In-House User Manual

Page 58: Zone

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Zone

Zone

VCM, VCM-X & VCB-X Controllers

SMTS II Technical Guide

58

VCB-X Controllers

VCB-X Staging Delay Setpoints

Fan Starting Delay

Enter the number of seconds you want the fan to delay starting. This is
the Supply Fan Starting Delay initiated whenever the VCB-X initiates
Supply Fan operation upon going occupied or after power-up. This is
useful when you are using multiple VCB-X-controlled HVAC units and
want to be sure that all the units do not start at exactly the same time
when the Occupied schedule occurs. Each VCB-X should be set with
staggered Fan Starting Delay Setpoint values. When the -1 value is used,
it multiplies each VCB-X Controller’s address by 5 and uses this value
in seconds as the Fan Starting Delay. This provides a staggered start for
each VCB-X Controller on the system without having to individually
set each VCB-X Controller for its own time delay. High limit = 240
seconds; Low limit = -1 second; Default = -1 second.

Fan Purge Mode Delay

This is the number of seconds you want the unit to stay in Purge Mode
before going into Occupied Mode. In Purge Mode, the fan runs with
the Economizer at minimum position and all Cooling and Heating is
de-energized. High limit = 900 seconds; Low limit = 0 seconds; Default
= 10 seconds.

Static/ Fan Speed Control Rate

This value determines the time interval between changes to the Supply
Fan Speed or the Bypass Damper Position during duct static pressure
control. It also determines the time interval between changes to the Fan
Speed during Single Zone VAV Reset of the Supply Fan VFD Speed.
High limit = 30 seconds; Low limit = 1 second; Default = 10 seconds.

Heat Pump Defrost Interval

If this is a Heat Pump unit with a Defrost Coil Temperature Switch
installed and confi gured, a Heat Pump Defrost Mode is available. If
the Defrost Coil Temperature Switch closes during Heat Pump Heating
operation, the unit will enter the Defrost Mode for 10 minutes or until
the Defrost Coil Temperature Switch opens. The Heat Pump Defrost
Interval is the length of time that must be met between Defrost Modes.
The length of this Defrost Interval can be automatically adjusted by the
Heat Pump Defrost Adaptive Timer. High limit = 120 minutes; Low
limit = 10 minutes; Default = 30 minutes.

Heat Pump Defrost Adaptive Timer

Once initiated, the Defrost Mode is active until the Defrost Coil Tem-
perature Switch opens or until a 10 minute timer has expired. Enter a
value greater than zero to enable the Adaptive Defrost Adjustment of the
Heat Pump Defrost Interval. This adjustment value will be subtracted
from the Heat Pump Defrost Interval if the Defrost Mode lasts the entire
10 minutes. A proportion of this adjustment value will be added to the
Heat Pump Defrost Interval if the Defrost Mode only lasts between 8
minutes and 0 minutes. High limit = 30 minutes; Low limit = 0 minutes;
Default = 0 minutes.

Warmup Mode Timeout Period

This sets the amount of time the unit can remain in Warmup Mode if the
Return Air still hasn’t reached its target temperature. High limit = 240
minutes; Low limit = 0 minutes; Default = 60 minutes.

Trendlog Interval

An internal Trend Log is constantly updated at a rate equal to this value.
Trend Logs can only be accessed with Prism 2 software. High limit =
120 minutes; Low limit = 1 minutes; Default = 15 minutes.

Setpoints for Unit 0001

Fan Starting Delay

Heat Pump Defrost Interval

Heat Pump Defrost Adaptive Timer

240

30

0

Sec

Fan Purge Mode Delay

Static / Fan Speed Control Rate

10

10

Staging Delays

Page 4 of 5

Sec

Sec

Sec

Sec

Figure 110: VCB-X Staging Delay Setpoints Screen 4

Setpoints for Unit 0001

Warmup Mode Timeout Period

60

Min

Trendlog Interval

15

Staging Delays

Page 5 of 5

Min

Figure 111: VCB-X Staging Delay Setpoints Screen 5

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