How to use SUR with restriction in R?

Question

I ran an SUR model in R using systemfit package, but I need to take the summary result and use it for imposing two restrictions:

1. the sum of the intercepts of the three equations should be equal to 24.
2. the sum of the coefficients of each explanatory variable over all the activities is equal to zero.

How do I run an SUR model with these two restriction?

SUR estimates for 'eq1' (equation 1)
Model Formula: Y1 ~ X1

                    Estimate  Std. Error   t value
(Intercept)       8.12788487  1.22300735   6.64582
X1Rural          -1.03309385  0.38727326  -2.66761
X1chdlessthan6    1.67758437  0.39414610   4.25625




SUR estimates for 'eq2' (equation 2)
Model Formula: Y2 ~ X1

                   Estimate Std. Error  t value             Pr(>|t|)
(Intercept)       0.7163935  0.9913563  0.72264             0.470431
X1Rural          -0.7947226  0.3139194 -2.53161             0.011834
X1chdlessthan6   -0.5248445  0.3194905 -1.64275             0.101419


                    


SUR estimates for 'eq3' (equation 3)
Model Formula: Y3 ~ X1

                   Estimate Std. Error  t value               Pr(>|t|)
(Intercept)      19.9376084  1.5112688 13.19263 < 0.000000000000000222
X1Rural           0.3432570  0.4785531  0.71728             0.47372572
X1chdlessthan6   -1.3580186  0.4870459 -2.78828             0.00561697

                    

I tried linearhypothesis, but I was getting an error saying The hypothesis "Y1_(Intercept)+Y2_(Intercept)+Y3_(Intercept)=24" is not well formed: contains bad coefficient/variable names.