Factory Default Settings; Installation - Hoffman Controls 890-DSQ Series Complete Installation & Operating Instructions

Operating Modes Con't
NOTE:
The LCD's Home Screen will show "VS: 0" indicat-
ing the EC motor is at lowest speed. However, the PWM
and VDC output signals will remain set at 15% PWM and
1.5 VDC, until the VarFan SpdLimits OutputOff: value is
reached (see menu 9 below).
9) VarFan SpdLimits OutputOff: 0
Scales the sequencer's PWM and VDC output signals to
match the selected VS (variable stage) EC motor's off percent-
age. When the sequencer's input temperature sensor (or pres-
sure transducer) value drops below the EC motor's turn on
value (set in MODE 4.1a or 4.2a
put signals will linearly decrease from the VarFan SpdLimits
OutputLow: value, to the VarFan SpdLimits OutputOff:
value, over a 2 °F (or 2 PSI) span, to keep the EC motors from
short cycling.
As the input sensor's value continues to decrease, the PWM
and VDC output signal's percentage will remain set at the
VarFan SpdLimits OutputOff: value.
For example:
1) When the sequencer's VS (variable stage's) output signals
are required to decrease to 0% PWM or 0 VDC to turn off the
fan, the VarFan SpdLimits OutputOff: value must be set to
" ".
0
2)
When the sequencer's VS (variable stage's) output signals
are required to decrease to 5% of their full capability, and
remain at 5%, as the input signal continues to decrease, the
VarFan SpdLimits OutputOff: value should be set to "5"
NOTE:
The LCD's Home Screen will continue to show "VS: 0",
indicating the EC motor is still off. However, the PWM and
VDC output signals will remain at the PWM and VDC per-
centages set by the VarFan SpdLimits OutputOff: value
10-0 VDC Output Selection
When the variable stage EC motors require a 10-0 VDC
control signal, the VDC output's 0-10 VDC signal can be
inverted (changed to a 10-0 VDC signal) by doing the follow-
ing: (This will also invert the PWM duty cycle)
1) Set the "VarFan SpdLimits OutputHigh:" value to a low
number (usually between 0 and 15).
2) Set the "VarFan SpdLimits OutputLow:" value to a high
number (usually between 80 and 90).
3) Set the "VarFan SpdLimits OutputOff:" value to the
highest number (usually between 95 and 100).
For Example:
To set the EC motor's control signal for full speed at 0 VDC,
minimum speed at 7.7 VDC and off at 9.5 VDC, use:
VarFan SpdLimits OutputHigh: 0
VarFan SpdLimits OutputLow: 77
VarFan SpdLimits OutputOff: 95
)
, the PWM and VDC out-
.
.
Using motors with a 10-0 VDC input control signal pro-
vides a level of safety. If the EC motors using a 10-0 VDC
input signal loose their control signal they will run at full
speed.
10) Reset Control To Factory Settings?
No
Use the UP and DOWN buttons to change the No to a Yes,
or vice versa. Then press the ENTER button when the answer
is correct.
This completes the Operating Modes section.

Factory Default Settings

The 890-DSQ Sequencer's factory default settings are:
Test fans on = 0 (none).
Is variable stage used? No.
Number of fixed stages used = 4 relay output stages.
Stage on delay = 2 seconds.
Number of input stages used = 2 input stage.
Input combine rule = maximum.
Emergency on = 95 °F, 950 PSI or 9.5 VDC.
Change primary set points = No.
Change secondary set points = No.
Lockout enabled? No.
Modbus slave address = 1.
Modbus BAUD rate = Code 4 (19200).
Modbus parity = Even Parity.
Sensor type = Temperature.
Relay sequence = FILO.
Reset control to factory sets? No.

Installation

IMPORTANT:
Do not install the sequencer in an airtight compart-
ment, on a vibrating surface or near/on heat
generating sources.
IMPORTANT:
The 890-DSQ Sequencer's relay output stages are
only designed for low voltage (24 VAC) operation.
Operating the relay output stages at higher voltages
may result in permanent damage to the sequencer.
9